• 제목/요약/키워드: Rational number

검색결과 400건 처리시간 0.024초

인더스트리얼 디자인에 있어서의 생산성 개념과 측정방법 (Productivity Concept and Measuaring Mathod of Industrial Design)

  • 이수봉
    • 디자인학연구
    • /
    • 제14권
    • /
    • pp.181-191
    • /
    • 1996
  • $\ulcorner$ID생산성$\lrcorner$이란 $\ulcorner$인더스트리얼 디자인$\lrcorner$(Industrial Design; 이하 ID로 약칭)과 $\ulcorner$생산성$\lrcorner$(Productivity)을 결합한 용어로서 그 개념은 상품의 디자인개발에 투입된 모든 디자인자원 및 요소의 효율적인 이용도를 나타내는 지표로 설명될 수 있다. $\ulcorner$ID생산성$\lrcorner$은객관 적인 방법과 주관적인 방법 두 가지 측면에서 측정 할 수 있다. 전자는 투입과 산출의 관계를 가능한 객관적, 정량적으로 분석한다는 방식이며, 후자는 ID의 방법 자체가 극히 주관적이라는 특성을 전제로 하여 $\ulcorner$ID생산성$\lrcorner$을 가능한 한 정상적으로 분석하는 방법이다. 전자는 디자인 시간, 디자이너 수 , 경비를 공통의 투입요소로 사용하여 개인별.요소별.디자인문문 전체의 디자인 생산성 측정 그 자체가 불가능하며 신뢰성이 없는 단점이 있다. 후자는 Good Design을 산출요소로 사용하여 개인 및 디자인 부문 전체의 합리적 디자인 생산성 측정이 가능한 반면, 주관적 평가를 위한 설문조사나 분석방법 절차 등이 번거러운 단점이 있다. 그러나 이 방법은 전자보다는 매우 합리적이며 신뢰도가 높다는 이점이 있다.

  • PDF

Perceptions of Contraception and Patterns of Switching Contraceptive Methods Among Family-planning Acceptors in West Nusa Tenggara, Indonesia

  • Amran, Yuli;Nasir, Narila Mutia;Dachlia, Dini;Yelda, Fitra;Utomo, Budi;Ariawan, Iwan;Damayanti, Rita
    • Journal of Preventive Medicine and Public Health
    • /
    • 제52권4호
    • /
    • pp.258-264
    • /
    • 2019
  • Objectives: The perceptions of family-planning (FP) acceptors regarding contraception influence the reasons for which they choose to switch their method of contraception. The objective of this study was to analyze the perceptions of contraception and rationales for switching contraceptive methods among female FP acceptors in West Nusa Tenggara, Indonesia. Methods: This study involved the analysis of secondary data from the Improve Contraceptive Method Mix study, which was conducted in 2013 by the Center for Health Research, University of Indonesia. The design of the study was cross-sectional. We performed 3 stages of sampling using the cluster technique and selected 4819 women who were FP acceptors in West Nusa Tenggara Province, Indonesia as the subjects of this study. The data were analyzed using multiple logistic regression. Results: The predominant pattern of switching contraceptive methods was switching from one non-long-term method of contraception to another. Only 31.0% of the acceptors reported a rational pattern of switching contraceptive methods given their age, number of children, and FP motivations. Perceptions of the side effects of contraceptive methods, the ease of contraceptive use, and the cost of the contraceptives were significantly associated (at the level of ${\alpha}=0.05$) with rational patterns of switching contraceptive methods. Conclusions: Perceptions among FP-accepting women were found to play an important role in their patterns of switching contraceptive methods. Hence, fostering a better understanding of contraception through high-quality counseling is needed to improve perceptions and thereby to encourage rational, effective, and efficient contraceptive use.

GIS를 이용한 계룡산국립공원 제2집단시설지구개발의 수문영향파악 (Application of the GIS in the Hydrologic Effects Caused by the Second Collective Facility Area Development in Mt. Kyeryong National Park)

  • 예우성;이희선;이규석
    • 환경영향평가
    • /
    • 제3권2호
    • /
    • pp.57-67
    • /
    • 1994
  • The National Park should be preserved as described in the regulation. However, the development has resulted in degrading the environment in the park. Especially, the collective facility area has been developed for the commercial benefit rather than for the preservation. So, it is necessary to figure out the impact of the development plan proposed. Thus, the purpose of this study is to explore the hydrologic effects due to the collective facility area development in the National Park. The study site is the second collective facility area of Mt. Kyeryong National Park. The analysis of hydrologic effects due to the development has been carried out using the GIS in this study. The Rational Method and Soil Conservation Service(SCS) were used to estimate the runoff volume. During this procedure, GIS software, ARC/INFO was used to integrate, manipulate, and calculate the attribute value of a number of ploygons which represen each land use characteristic. A program was written to compute the attribute value of each polygon and to estimate the difference of peaktime runoff volume before and after development.

  • PDF

부산지역 오존 및 이산화질소 농도의 공간분포해석에 따른 대기오염측정망 배치연구 (A Study on Allocation of Air Pollution Monitoring Network by Spatial Distribution Analysis of Ozone and Nitrogen Dioxide Concentrations in Busan)

  • 유은철;박옥현
    • 한국대기환경학회지
    • /
    • 제20권5호
    • /
    • pp.583-591
    • /
    • 2004
  • In this study, methodologies for the rational organization of air pollution monitoring network were examined by understanding the characteristics of temporal and spatial distribution of secondary air pollution, whose significance would increase hereafter. The data on $O_3$ and $NO_2$ concentrations during high ozone period in 1998~1999 recorded at the nine air pollution monitoring station in Busan were analysed using principal component analysis (PCA) and cumulative semivariogram. It was found that the ozone concentration was deeply associated with the daily emission characteristics or the $O_3$ precusors, and nitrogen dioxide concentration largely depends on the emission strength of regional sources. According to the spatial distribution analysis of ozone and nitrogen dioxide in Busan using cumulative semivariograms, the number of monitoring stations for the secondary air pollution can be reduced in east-west direction, but reinforced in north-south direction to explain the spacial variability. More scientific and rational relocation of air pollution monitoring network in Busan would be needed to investigate pollution status accurately and to plan and implement the pollution reduction policies effectively.

역공학에서 센서융합에 의한 효율적인 데이터 획득 (Efficient Digitizing in Reverse Engineering By Sensor Fusion)

  • 박영근;고태조;김희술
    • 한국정밀공학회지
    • /
    • 제18권9호
    • /
    • pp.61-70
    • /
    • 2001
  • This paper introduces a new digitization method with sensor fusion for shape measurement in reverse engineering. Digitization can be classified into contact and non-contact type according to the measurement devices. Important thing in digitization is speed and accuracy. The former is excellent in speed and the latter is good for accuracy. Sensor fusion in digitization intends to incorporate the merits of both types so that the system can be automatized. Firstly, non-contact sensor with vision system acquires coarse 3D point data rapidly. This process is needed to identify and loco]ice the object located at unknown position on the table. Secondly, accurate 3D point data can be automatically obtained using scanning probe based on the previously measured coarse 3D point data. In the research, a great number of measuring points of equi-distance were instructed along the line acquired by the vision system. Finally, the digitized 3D point data are approximated to the rational B-spline surface equation, and the free-formed surface information can be transferred to a commercial CAD/CAM system via IGES translation in order to machine the modeled geometric shape.

  • PDF

철도지하횡단 통과 공법 선정기준에 관한 검토를 통해 효율적인 적용성에 대한 연구 (Research on Efficient Applicability Through Review on Standard for Selection of Construction Method for Railway Underground Crossing Transit)

  • 황영호;손정철;백종명
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2007년도 추계학술대회 논문집
    • /
    • pp.595-600
    • /
    • 2007
  • Greater expansion and more frequent operation of the railroad transportation system anticipated due to its characteristics including low cost, safety and mass transportation. Recently, effects on the railway structures due to expansion of newly constructed road, construction of subway, city gas pipeline, communication network, electric power network and construction of other railway underground crossing in accordance with urban planning and organization has influenced safe operation of trains. Accordingly, standard for selection of construction method that will enable construction of more economical and rational subway underground crossing structures by preventing problems occurring at the time of above construction works and accidents in safe operation of trains due to construction in advance is definitively necessary. Although there are numerous construction methods that can be applied at the time of construction of railway underground crossing, there are much difficulties in selection of appropriate construction method that considers characteristics of each construction method on non-excavation type construction method, train operation plan of number of operational routes and on-site circumstances. Therefore, this research aims to present rational standard for selection of construction method for such, and standard for slowdown speed and interception of train when passing the areas of slowdown in sectors under construction.

  • PDF

A new damage index for reinforced concrete structures

  • Cao, Vui V.;Ronagh, Hamid R.;Ashraf, Mahmud;Baji, Hassan
    • Earthquakes and Structures
    • /
    • 제6권6호
    • /
    • pp.581-609
    • /
    • 2014
  • Reinforced concrete (RC) structures are likely to experience damage when subjected to earthquakes. Damage index (DI) has been recognised as an advanced tool of quantitatively expressing the extent of damage in such structures. Last 30 years have seen many concepts for DI proposed in order to calibrate the observed levels of damage. The current research briefly reviews all available concepts and investigates their relative merits and limitations with a view to proposing a new concept based on residual deformation. Currently available DIs are classified into two broad categories - non-cumulative DI and cumulative DI. Non-cumulative DIs do not include the effects of cyclic loading, whilst the cumulative concepts produce more rational indication of the level of damage in case of earthquake excitations. Ideally, a DI should vary within a scale of 0 to 1 with 0 representing the state of elastic response, and 1 referring to the state of total collapse. Some of the available DIs do not satisfy these criteria. A new DI based on energy is proposed herein and its performances, both for static and for cyclic loadings, are compared with those obtained using the most widely accepted DI in literature. The proposed DI demonstrates a rational way to predict the extent of damage for a number of case studies. More research is encouraged to address some identified issues.

Closed Queueing Networks and Zeros of Successive Derivatives

  • Namn, Su-Hyeon
    • 한국경영과학회지
    • /
    • 제22권1호
    • /
    • pp.101-121
    • /
    • 1997
  • Consider a Jackson type closed queueing network in which each queue has a single exponential server. Assume that N customers are moving among .kappa. queues. We propose a candidata procedure which yields a lower bound of the network throughput which is sharper than those which are currently available : Let (.rho.$_{1}$, ... .rho.$_{\kappa}$) be the loading vector, let x be a real number with 0 .leq. x .leq. N, and let y(x) denote that y is a function of x and be the unique positive solution of the equation. .sum.$_{i = 1}$$^{\kappa}$y(x) .rho.$_{i}$ (N - y(x) x $p_{i}$ ) = 1 Whitt [17] has shown that y(N) is a lower bound for the throughput. In this paper, we present evidence that y(N -1) is also a lower bound. In dosing so, we are led to formulate a rather general conjecture on 'quot;Migrating Critical Points'quot; (MCP). The .MCP. conjecture asserts that zeros of successive derivatives of certain rational functions migrate at an accelerating rate. We provide a proof of MCP in the polynomial case and some other special cases, including that in which the rational function has exactly two real poles and fewer than three real zeros.tion has exactly two real poles and fewer than three real zeros.

  • PDF

NURB곡면을 이용한 3차원 절연설계 알고리즘과 그 응용 (Three-Dimensional Insulation Design Algorithm Using NURB Surface and Its Application)

  • 이병윤;명성호;한인수;박종근;김응식;민석원;신영준
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1997년도 하계학술대회 논문집 E
    • /
    • pp.1684-1687
    • /
    • 1997
  • In this paper, a three-dimensional algorithm for the insulation design of the high-voltage equipment is presented. In general, the insulation design consists of two steps. They are electric field calculation and correction of the shape to be designed. In the proposed algorithm, the combination method of charge simulation and surface charge simulation is used to calculate the three-dimensional electric fields. As for the correction of the shape, indirect control provided by rational B-spline is more useful than direct control. The use of rational B-spline reduces in the number of design variables and garrantees the smooth curvature of the designed shape. The proposed algorithm is applied to the design of the shape of the shield ring which has been designed by the method of trial and error.

  • PDF

RELATIONSHIPS BETWEEN CUSP POINTS IN THE EXTENDED MODULAR GROUP AND FIBONACCI NUMBERS

  • Koruoglu, Ozden;Sarica, Sule Kaymak;Demir, Bilal;Kaymak, A. Furkan
    • 호남수학학술지
    • /
    • 제41권3호
    • /
    • pp.569-579
    • /
    • 2019
  • Cusp (parabolic) points in the extended modular group ${\bar{\Gamma}}$ are basically the images of infinity under the group elements. This implies that the cusp points of ${\bar{\Gamma}}$ are just rational numbers and the set of cusp points is $Q_{\infty}=Q{\cup}\{{\infty}\}$.The Farey graph F is the graph whose set of vertices is $Q_{\infty}$ and whose edges join each pair of Farey neighbours. Each rational number x has an integer continued fraction expansion (ICF) $x=[b_1,{\cdots},b_n]$. We get a path from ${\infty}$ to x in F as $<{\infty},C_1,{\cdots},C_n>$ for each ICF. In this study, we investigate relationships between Fibonacci numbers, Farey graph, extended modular group and ICF. Also, we give a computer program that computes the geodesics, block forms and matrix represantations.