• 제목/요약/키워드: Basic Length Unit

검색결과 101건 처리시간 0.022초

초등학교 과학 교과서에서 사용되는 단위에 대한 아동들의 이해도 (Children서s Understanding on Scientific Units in Elementary School Science Textbooks)

  • 김성규;서승조;조태호;백남권;박강은;공정선
    • 한국초등과학교육학회지:초등과학교육
    • /
    • 제21권2호
    • /
    • pp.201-212
    • /
    • 2002
  • This paper aims to find out how did elementary students understand scientific units in science textbooks. The subjects were 191 students of the 6th grade from 7 elementary schools in 3 different areas, consisting of 70 from 4 village schools of, 64 from 2 town schools of Gyeongnam province, and 57 from one city school in Ulsan Metro City. A test was developed based on the analysis of scientific units in the science textbooks and teacher's manuals constructed according to the 6th and 7th National Science Curriculum. The understanding of elementary students' on the scientific units(Temperature, Length, Weight, Volume, Speed, Plane Angle) were surveyed. The result are as follows: Regarding the temperature unit, the students generally well understand why to measure and how to read temperature, but had some problem in recording it, in confusion with the plane angle sign. As for the length unit, they obtained high scores in understanding the purpose of measuring length as well as recording and reading it. Which indicates that they are well aware of and use the unit appropriately. With respect to the weight unit, they got high scores in reading and recording weight, which means most students have no problem using the unit. However, it was found that they do not understand why to use the plate balance scale. The volume unit was one in which the students got relatively lower scores. They do not perceive the object of using a scale cylinder and confuse it with a device of length measurement. The unit of speed is the most difficult one for children's of science to understand, presumably, because it is an derived unit from two basic units. It is also assumed that the students got the highest score in the plane angle unit because they studied the unit immediately before the test. From the children's understanding of science units above the teacher's understanding and teaching methods presumed to play a major role for children to understand and use the science units properly.

  • PDF

연결특성함수를 이용한 문서화상에서의 영역 분리와 문자열 추출 (Segmentation of region strings using connection-characteristic function)

  • 김석태;이대원;박찬용;남궁재찬
    • 한국통신학회논문지
    • /
    • 제22권11호
    • /
    • pp.2531-2542
    • /
    • 1997
  • This paper describes a method for region segmentation and string extractionin documents which are mixed with text, graphic and picture images by the use of the structural characteristic of connceted components. In segmentation of non-text regionas, with connection-characteristic functions which are made by structural characteristic of connected components, segmentation process is progressed. In the string extraction, first we organize basic-unit-region of which vertical and horizontal length are 1/4 of average length of connection components. Second, by merging the basic-unit-regions one other that have smaller values than a given connection intensity threshold. Third, by linking the word blocks with similar block anagles, initial strings are cresed. Finally the whold strings are generated by merging remaining word blocks whose angles are not decided, if their height and prosition are similar to the initial strings. This method can extract strings that are neither horizontal nor of various character sizes. Through computer exteriments with different style documents, we have shown that the feasibility of our method successes.

  • PDF

CNC 공작기계의 3차원 직선 및 원호 보간 알고리즘에 관한 연구 (3D Linear and Circular Interpolation Algorithm for CNC Machines)

  • 양민양;홍원표
    • 한국정밀공학회지
    • /
    • 제16권9호
    • /
    • pp.172-178
    • /
    • 1999
  • 3D linear and circular interpolations are a basic part for the machining of complex shapes. Until now, because of the absence of appropriate algorithms for the generation of 3D lines and circles, a full accomplishment for available machine tool resolution is difficult. this paper presents new algorithms for 3D linear and circular interpolation in the reference pulse technique. In 3D space, the line or circle is not expressed as an implicit function, it is only defined as the intersection of two surfaces. A 3D line is defined as the intersection of two planes, and a 3D circle is defined as the intersection of a plane and the surface of a sphere. Based on these concepts, interpolation algorithms are designed to follow intersection curves in 3D space, and a real-time 3D linear and circular interpolator was developed in software using a PC. The algorithm implemented in a PC showed promising results in interpolation error and speed performance. It is expected that it can be applied to the next generation computerized numerical control systems for the machining of 3D lines, circles and some other complex shapes.

  • PDF

Prediction of Length of ICU Stay Using Data-mining Techniques: an Example of Old Critically Ill Postoperative Gastric Cancer Patients

  • Zhang, Xiao-Chun;Zhang, Zhi-Dan;Huang, De-Sheng
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제13권1호
    • /
    • pp.97-101
    • /
    • 2012
  • Objective: With the background of aging population in China and advances in clinical medicine, the amount of operations on old patients increases correspondingly, which imposes increasing challenges to critical care medicine and geriatrics. The study was designed to describe information on the length of ICU stay from a single institution experience of old critically ill gastric cancer patients after surgery and the framework of incorporating data-mining techniques into the prediction. Methods: A retrospective design was adopted to collect the consecutive data about patients aged 60 or over with a gastric cancer diagnosis after surgery in an adult intensive care unit in a medical university hospital in Shenyang, China, from January 2010 to March 2011. Characteristics of patients and the length their ICU stay were gathered for analysis by univariate and multivariate Cox regression to examine the relationship with potential candidate factors. A regression tree was constructed to predict the length of ICU stay and explore the important indicators. Results: Multivariate Cox analysis found that shock and nutrition support need were statistically significant risk factors for prolonged length of ICU stay. Altogether, eight variables entered the regression model, including age, APACHE II score, SOFA score, shock, respiratory system dysfunction, circulation system dysfunction, diabetes and nutrition support need. The regression tree indicated comorbidity of two or more kinds of shock as the most important factor for prolonged length of ICU stay in the studied sample. Conclusions: Comorbidity of two or more kinds of shock is the most important factor of length of ICU stay in the studied sample. Since there are differences of ICU patient characteristics between wards and hospitals, consideration of the data-mining technique should be given by the intensivists as a length of ICU stay prediction tool.

BIM 기반 형상코드를 이용한 내력벽 철근길이 자동 산정 기초 연구 (A Basic Study of Automatic Rebar Length Estimate Algorithm of Bearing Wall by Using BIM-Based Shape Codes Built in Revit)

  • 임지영;김선국
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
    • /
    • pp.79-80
    • /
    • 2023
  • Reinforced concrete structures require large amounts of concrete and rebar in the construction stage. Rebar is a major resource for reinforced concrete structures, and generates more CO2 per unit weight than other materials. To solve this problem, it was confirmed that the cutting waste can be close to zero when the special length of the rebar is calculated in the drawing created after structural design. However, a system for automatically calculating the length of reinforcing bars to efficiently calculate the total amount of reinforcing bars has not been established. Therefore, the objective of this study is a basic study of automatic rebar length estimate algorithm of bearing wall by using BIM-based shape codes built in Revit. The bearing wall rebar can be automatically derived using the developed model. Furthermore, through applying the developed model to the construction field, it will greatly contribute to reducing greenhouse gas emissions by reducing rebar cutting waste.

  • PDF

연장된 보증을 갖는 예방보전모형 (Preventive maintenance model with extended warranty)

  • 정기문
    • Journal of the Korean Data and Information Science Society
    • /
    • 제24권4호
    • /
    • pp.773-781
    • /
    • 2013
  • 최근에 기본 보증이 종료된 이후에 주어지는 시스템의 연장된 보증에 대한 관심이 증가되고 있다. 따라서 본 논문에서는 사용자 측면에서 최소수리보증이 있는 연장된 보증이 종료된 이후의 예방보전모형을 제안하였다. 이 때, 기본 보증과 연장된 보증 하에서 고장이 발생된 시스템에는 판매자에 의해서 무료로 최소수리가 이루어진다. 이러한 제안된 예방보전모형에 대하여 기대순환길이, 총기대비용 그리고 단위시간당 기대비용을 유도하였다. 또한, 유도된 단위시간당 기대비용을 최소화 하는 최적의 예방보전 주기와 예방보전 횟수를 결정하였다. 끝으로 시스템의 고장시간이 와이블 분포를 따를 때 수치적 예를 통하여 이를 설명하였다.

중환자실 간호사의 업무부담 관련 요인: 체계적 문헌고찰 및 메타분석 (Factors Related to Workload of Intensive Care Unit Nurses: Systematic Review and Meta-Analysis)

  • 정아인;신수진;홍은민
    • 임상간호연구
    • /
    • 제29권3호
    • /
    • pp.296-311
    • /
    • 2023
  • Purpose: This study aimed to identify factors related to the workload of intensive care unit nurses through a systematic literature review and meta-analysis to provide basic data to explore the direction of development of nursing staffing standards. Methods: This study involved quantitative studies about nurses working in intensive care units related to nursing workload published in English or Korean since 2000. Search terms included 'intensive care unit', 'nursing workload', and their variations. Databases such as RISS, DBpia, MEDLINE(PubMed), CINAHL, PsycINFO, and Web of Science were utilized. Quality assessment was conducted using the Joanna Briggs Institute's Critical Appraisal Checklist for Analytical Cross-Sectional Studies. JAMOVI software facilitated the analysis of effect sizes, employing a meta-analysis approach for 7 studies with correlational or regression data. Results: From 16 studies on the workload of intensive care unit nurses, a total of 20 patient and nurse-related factors were identified. Patient-related factors included severity of illness, length of stay, and age. Meta-analysis was conducted for three patient-related factors: age, severity of illness measured by SAPS 3, and length of stay. Only severity of illness measured by SAPS 3 was significantly associated with nurse workload (Zr=0.16, p<.001, 95% CI=0.09-0.24). Conclusion: In previous studies, the characteristics of intensive care units and patients varied across studies, and a variety of scales for measuring workload and severity of illness were also used. Sustained research reflecting domestic intensive care unit work environments and assessing the workload of intensive care unit nurses should be imperative.

유료 재생교체-비재생수리보증이 종료된 이후의 최적의 교체정책 (Optimal replacement policy following the expiration of payable RRNMW)

  • 정기문
    • 한국신뢰성학회지:신뢰성응용연구
    • /
    • 제11권4호
    • /
    • pp.409-417
    • /
    • 2011
  • In this paper, we consider a replacement model following the expiration of warranty. In other words, this paper proposes the optimal replacement policy for a repairable system following the expiration of payable renewing replacement-non-renewing minimal repair warranty. The expected cost rate per unit time from the user's perspective is used to determine the optimality of the replacement policy. Thus, we derive the expressions for the expected cycle length and the expected total cost to obtain the expected cost rate per unit time. Finally, the numerical examples are presented for illustrative purpose.

A High-Security RSA Cryptoprocessor Embedded with an Efficient MAC Unit

  • Moon, Sang-Ook
    • Journal of information and communication convergence engineering
    • /
    • 제7권4호
    • /
    • pp.516-520
    • /
    • 2009
  • RSA crypto-processors equipped with more than 1024 bits of key space handle the entire key stream in units of blocks. The RSA processor which will be the target design in this paper defines the length of the basic word as 128 bits, and uses an 256-bits register as the accumulator. For efficient execution of 128-bit multiplication, 32b*32b multiplier was designed and adopted and the results are stored in 8 separate 128-bit registers according to the status flag. In this paper, an efficient method to execute 128-bit MAC (multiplication and accumulation) operation is proposed. The suggested method pre-analyzed the all possible cases so that the MAC unit can remove unnecessary calculations to speed up the execution. The proposed architecture prototype of the MAC unit was automatically synthesized, and successfully operated at 20MHz, which will be the operation frequency in the RSA processor.

연장된 이단계 보증 이후의 교체모형 (Replacement Model after Extended Two-phase Warranty)

  • 정기문
    • 통합자연과학논문집
    • /
    • 제14권4호
    • /
    • pp.197-204
    • /
    • 2021
  • Under the two-phase warranty, the warranty period is divided into two intervals, one of which is for renewing replacement warranty, and the other is for minimal repair warranty. Jung[13] discusses the two types of extended two-phase warranty models. In this paper, we suggest the replacement model after the extended two-phase warranty that has been proposed by Jung[13]. To determine the optimal replacement policy, we adopt the expected cost rate per unit time. So, the expressions for the total expected cost, the expected length of the cycle and the expected cost rate per unit time from the user's point of view are derived. Also, we discuss the optimal replacement policy and the uniqueness of the solution for the optimization. Furthermore, the numerical examples are provided to illustrate the proposed the replacement model.