• Title/Summary/Keyword: direct measure

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Theories and Measurement Techniques for LAI of Crops (밭작물의 엽면적지수(LAI)에 대한 이론 및 측정기술)

  • Park, Jong-Hwa;Lee, Sang-Hyuk;Shin, Yong-Hee;Park, Min-Seo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.21-24
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    • 2002
  • Many methods are available to measure leaf area index(LAI) directly and are variations of either Leaf area index(LAI) and leaf angle distribution are widely used indices of canopy structure that are difficult to measure directly. Direct measurements of canopy structure are tedious and labor intensive in small canopies and nearly impossible in large forest canopies. This study introduced fundamental theories in LAI measurements and applied that for several crops.

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A Study on the Tappet Rotation in the Direct Acting Type OHC Valve Train System (직접 구동형 OHC 밸브 트레인 시스템의 태핏 회전에 관한 연구)

  • 한동철;김형준;조명래
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.04a
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    • pp.286-291
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    • 1998
  • The aim of this paper is to measure the tappet rotation in OHC valve train system. Tappet is eccentric from the cam center to rotate for preventing the partial wear. The experimental system is developed to measure the tappet rotation by using the laser beam and optical fiber. The characteristics of tappet rotation is presented for various operating conctitions. Specially, it is observed that tappet is rotated at the base circle.

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Measuring Importance of Online Apparel Stores' Design Attributes Using Three Different Methods

  • Oh, Keunyoung;Lee, MiYoung
    • Journal of Fashion Business
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    • v.19 no.6
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    • pp.127-138
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    • 2015
  • Due to the virtual nature of online businesses, online apparel stores need to enhance the consumer experience by utilizing store design attributes to provide their customers relevant and sufficient information. Since online apparel stores mainly communicate with their customers virtually and digitally, it is important to understand how consumers perceive and react to different design attributes commonly found on apparel stores' online websites. The purpose of this paper is to examine the importance of design attributes commonly found on online apparel stores' websites using three different importance measurements. The design attributes examined in this study include enlarged pictures, product detail pictures, product reviews by other buyers, coordinating items, and size measurement charts. The three different measurements used in this study include two direct measures and one indirect measure using conjoint analysis. Across the three different measures, both the men and women indicated that enlarged pictures represent the most important design attribute when they purchase clothes online followed by size measurement charts and they considered the availability of coordinating items the least important design attribute.

MOS Transistor Differential Amplifier (MOS Transistor를 이용한 착동증폭기)

  • 이병선
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.4 no.4
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    • pp.2-12
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    • 1967
  • A pair of insulated-gate metal-oxide-semiconductor field-effect transistor has been used to measure the direct current produced from the ionization chamber in the range of to A. An analisis of direct-current differential amplifier giving the expressions of the common-mode rejection ratio and the rralization of the constant-current generator to give very large effective source resistance has been presented. Voltage gain is 6.6, drift at the room temperature is 1.5mv per day. The common-mode rejection ratio is obtained maximum 84db. These facts give the feasibility of small direct-current measurements by utilizing this type transistors.

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A Study on a Measurement Method for 2D Anthropometry using Digital Camera (디지털 카메라를 이용한 2D 인체계측법 연구)

  • 손희정;김효숙;최창석;손희순;김창우
    • The Research Journal of the Costume Culture
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    • v.11 no.1
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    • pp.11-19
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    • 2003
  • This study suggests the new 2D anthropometric method using digital camera. It is used MK2001 program that can convert 2D measurements to 3D measurements. To improve that it is measured 100 college students with direct and indirect anthropometric method. The measurements were processed by the SPSS ver10 Statistical Package. The average, standard deviation, and t-test were calculated for each category. Most measurements by 2D measurements are higher than direct measurements but degree. The difference between direct and indirect measurements is less than 2cm. In the results of t-test, height measurements including other 16 measurements which is easy to measure have no meaningful difference within 1cm. The depth measurements are most high difference. The result of each measurement proves that MK2001 program (2D anthropometry method using digital camera) is available for measuring the human body.

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Mathematical Programming Approaches to GT Cell Formation: A Comparative Study

  • 원유경
    • Journal of the Korean Operations Research and Management Science Society
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    • v.16 no.2
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    • pp.137-137
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    • 1991
  • This paper compares and evaluates the performances of the two types of mathematical programming models for solving the machine-part cell formation problem in group technology manufacturing : indirect formulation relying on surrogate measure such as similarity coefficient and direct formulation seeking to minimize the number of exceptional elements. New indirect formulation, called the generalized p-median model. is proposed. Unlike existing p-median formulations, proposed formulation includes the classical cell formation problem in which only one process plan exsits for each part as a special case. The proposed new formulation can also deal with the cell formation problem in which alternative process plans exist for a part. The indirect formulation is compared with a new direct formulation which needs much fewer extra variables and constraints than existing direct formulations. Some significant findings from comparative experiment are discussed.

Controller design for compensation of nonlinear harmonic distortion in direct-radiator loudspeakers (직접 방사형 스피커의 비선형 고조파 왜곡 보상 제어기의 설계)

  • 김윤선;박영진
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.399-402
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    • 1996
  • The electrodynamic loudspeakers should have a wide dynamic range to reproduce various sound levels. When the input signal is small, the radiated sound from the loudspeaker is not so much distorted. However, for large input signal with low frequency component the radiated sound is significantly distorted due to the nonlinearities of the loudspeaker. The suspension, damping, and magnetic flux of loudspeaker are the main sources of the nonlinearity. Such electromechanical parameters related to harmonic distortion have been represented by a polynomial model for diaphragm displacement, while each of the polynomial coefficient is evaluated by using the principle of harmonic balance experimentally. Based on the polynomial model, we designed a compensator for nonlinear harmonic distortion of direct radiator loudspeaker. Than observer is used to estimate the displacement of the loudspeaker diaphragm, which is rather difficult to measure directly in the conventional setting. The usefulness of the designed compensator is demonstrated by numerical simulations. Simulation results show about 30db decrease at the second and third higher harmonic distortions. We carry out an experiment on speaker to verify designed controller and nonlinear observer.

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Development of Gasoline Direct Swirl Injector III (직접분사식 가솔린 선회분사기 개발에 관한 연구 III)

  • Part, Young-Kug;Oh, Jae-Geon;Lee, Choong-Won
    • Journal of ILASS-Korea
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    • v.6 no.4
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    • pp.39-48
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    • 2001
  • The Gasoline Direct Injection(GDI) system has been highlighted due to the improvement of fuel consumption and the control of exhaust emission from gasoline engines. Main purpose of the present study is to measure spray characteristics of GDSI for real engine application. We have investigated experimentally spray tip penetration, spray angle, tip velocity and spatial spray distribution. Counter-rotating vortex grown on the spray surface plays an important role in the spray characteristics. Accordingly the spray tip penetration and tip velocity do not excess 50mm, 20m/s respectively, under 0.6MPa ambient pressure. the spray cone angle of GDSI have a same tendency to a simplex swirl atomizer.

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Selection Responses for Milk, Fat and Protein Yields in Zimbabwean Holstein Cattle

  • Mandizha, S.;Makuza, S.M.;Mhlanga, F.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.7
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    • pp.883-887
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    • 2000
  • One way of evaluating the effectiveness of a dairy breeding program is to measure response to selection. This may be direct or indirect. The objectives of this study were to estimate expected progress for direct selection on milk, fat and protein yields; to estimate the expected correlated responses on indirect selection for milk, fat and protein yields in Zimbabwean Holstein cattle and to establish the effect of selection intensity on responses. The Animal Model contained fixed effects of herd, year of calving, calving month, dry period, milking frequency and additive effects pertaining to cows, sires and dams. AIREML software package was used to analyse the data. The genetic and phenotypic parameters obtained in this study were used to compute direct and correlated responses to selection. Because of the higher heritabilities in first parity, genetic progress was found to be greater when selection was practised on first parity cows as compared to later lactations. It is therefore recommended that older cows in the herd be replaced with improved heifers so as to enhance genetic progress.

Mathematical Programming Approaches to GT Cell Formation: A Comparative Study

  • 원유경
    • Korean Management Science Review
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    • v.16 no.2
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    • pp.137-147
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    • 1999
  • This paper compares and evaluates the performances of the two types of mathematical programming models for solving the machine-part cell formation problem in group technology manufacturing : indirect formulation relying on surrogate measure such as similarity coefficient and direct formulation seeking to minimize the number of exceptional elements. New indirect formulation, called the generalized {{{{ { p}_{ } }}-median model. is proposed. Unlike existing {{{{ { p}_{ } }}-median formulations, proposed formulation includes the classical cell formation problem in which only one process plan exsits for each part as a special case. The proposed new formulation can also deal with the cell formation problem in which alternative process plans exist for a part. The indirect formulation is compared with a new direct formulation which needs much fewer extra variables and constraints than existing direct formulations. Some significant findings from comparative experiment are discussed.

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