• Title/Summary/Keyword: indirect measure

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Indirect Cutting Force Estimation Using Artificial Neural Network (인공 신경망을 이용한 절삭력 간접 측정)

  • 최지현;김종원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.1054-1058
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    • 1995
  • There have been many research works for the indirect cutting force measurement in machining process, which deal with the case of one-axis cutting process. In multi-axis cutting process, the main difficulties to estimate the cutting forces occur when the feed direction is reversed. This paper presents the indirect cutting force measurement method in contour NC milling processes by using current signals of servo motors. An artificial neural network (ANN) system are suggested. An artificial neural network(ANN) system is also implemented with a training set of experimental cutting data to measure cutting force indirectly. The input variables of the ANN system are the motor currents and the feedrates of x and y-axis servo motors, and output variable is the cutting force of each axis. A series of experimental works on the circular interpolated contour milling process with the path of a complete circle has been performed. It is concluded that by comparing the ANN system with a dynamometer measuring cutting force directil, the ANN system has a good performance.

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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.

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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Development of an NC Machine Performance Test and Calibration System (수치제어 공작기계의 위치오차 측정 및 보정시스템 개발)

  • 이상윤;박준호;조선휘;김문상
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.6
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    • pp.1431-1440
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    • 1993
  • This paper presents a new NC machine performance test and calibration system. In order to measure NC machine erros in simpler, and less time-comsuming way, some indirect measuring systems such as circular disk system and double ball bar system have been developed instead of laser interferometer. But these indirect measuring systems have shown their limits in identifying each of NC machine error sources in absolute numerical value. Therefore, we developed an unique NC machine error measurement system which provides a simple measuring process like other conventional indirect methods and still can indentify each of NC machine error sources in absolute numerical value.

The Measurement of Detachment of Vane Tip in a Positive Displacement Small Vane Pump (압력 평형형 소형 베인펌프에서의 베인 이간 현상 측정)

  • 안형준;양광식;한동철;박민호
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.10a
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    • pp.365-370
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    • 1998
  • This paper reports on the measurement of the vane motion in a positive displacement small vane pump. The capacitive method using ceramic vane is proposed to measure the vane motion. This method enables us to measure only radial motion of the vane regardless of the motions of other directions. With simple experiments and solutions of simultaneous equations, the indirect compensation of measured signal was performed.

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Design of Room Lighting Switch Operated by Indirect Touch and Research on the Switching Sensitivity of Dielectric Materials On Electrode Metal (간접접촉형 실내조명 스위치의 설계 및 접촉부 절연물질별 스위칭 동작감도 고찰)

  • Choi, Joon-Young;Kang, Byung-Chul;Lee, Chang-Ik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.4
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    • pp.86-91
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    • 2009
  • Indirect Touch switch which detects the change of capacitance around the electrode of QT113H chip from QPROX is designed and assembled. Sensitivity analysis of dielectric materials which prevents electrodes from direct touch is performed and the results are displayed in tables and graphs. Glass, acryl, and MDF is used to insulate the electrode and to measure the operating sensitivity of indirect touch switch. While the difference of permittivity of the dielectric materials are large, it is confirmed that the operating sensitivity of each dielectric materials are not so large as the differences of those of dielectric materials.

A Plan of Safety Management through Identifying Causes of Fall Fatal Accidents in Korean Construction Industry (발생 원인 규명을 통한 국내 건설 추락 사망사고의 안전관리 방안)

  • Ham, Jung-Bin;Cha, Yongwoon;Han, Sangwon;Hyun, Chang-Taek
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.38-39
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    • 2014
  • In order to reduce fatal accidents, a systematic safety management should be performed at a construction site. A lot of researches on direct causes of fatal accidents and indirect causes which affect the direct causes have been conducted for effective safety management. In the previous studies, these causes are considered separately because of the difficulty of recognition of indirect causes. It is also hard to measure the negative impact of these causes and notice their occurrence the perception of its problem. However, a study on identification of complicated relationship between these two types of causes is necessary since an accident occurs due to the chain reaction that indirect causes trigger the direct causes which lead to the fatal accidents. Therefore, this study proposes a safety management plan that considers indirect and direct causes of fatal accidents cases in the Korean construction industry. Then this paper suggests a plan of safety management by identifying major causes of the accidents.

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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.

Cross Flow Indirect Evaporative Cooler Made of a Plastic Film/Paper Composite (플라스틱 필름/종이 복합 재질의 직교류 간접증발소자)

  • Kim, Nae-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.1
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    • pp.21-28
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    • 2017
  • Indirect evaporative cooling, which utilizes a cooling effect obtained by the evaporation of water, is energy-effective compared to the conventional vapor compression method. It is also eco-friendly, due to the non-usage of CFC refrigerant. In this study, three indirect evaporative cooler samples of the cross flow type(size: $300mm{\times}300mm{\times}300mm$, channel pitch: $5mm{\times}5mm$, $5mm{\times}7mm$, $7mm{\times}7mm$) were made using plastic/paper composites. Tests were conducted to measure indirect evaporative efficiencies and pressure drops. Results showed that the efficiency was the highest for the $5mm{\times}5mm$ sample, owing to the largest surface area. The saved electrical energy was also the greatest for that sample. The pressure drop of the wet channel was larger than that of the dry channel as expected. A theoretical model was proposed, which underestimated both the indirect evaporation efficiency and the pressure drop.

EFFECT OF IMPRESS10N TECHNIQUE ON THE ACCURACY OF MASTER CAST FOR IMPLANT PROSTHESIS (인상채득법이 임플랜트 주모형의 정확성에 미치는 영향)

  • Kim Young-Oh;Yang Hong-So;Vang Mong-Sook;Park Sang-Won;Park Ha-Ok;Lee Jai-Bong
    • The Journal of Korean Academy of Prosthodontics
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    • v.44 no.1
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    • pp.63-72
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    • 2006
  • Purpose: The purpose of this study was to compare the accuracy of master cast fabricated by using different impression methods at the different impression levels. Material and Method: The master model used in this study was resin block having low implant analogs. Impression method studied were 1) direct method on future level (Group FIX-D), 2) Indirect method on fixture level(Group FIX-I), 3) Modified indirect method on fixture level(Group FD(-M), 4) Direct method on abutment level(Group AB-D) and 5) Indirect method on abutment level(Group AB-I). Each of the five groups took 10 impressions. Fifty impressions were made for master cast by using Impregum $F^(R)$ impression material loaded on individual tray. Three dimensional measuring microscope was used to measure the inter-implant distance. Error rate of each inter-implant distance were calculated and evaluated. Results: The results were as follows. 1. Group FIX exhibited higher accuracy than group AB. 2 In group FIX, modified indirect method showed the highest accuracy, while indirect method showed the lowest accuracy. In group Ab, indirect method showed the higher accuracy than direct method. 3. Group FIX showed larger horizontal error than group AB. But, group AB showed the larger vertical error than group FIX. 4. Group Fix-M showed smallest vertical and horizontal error.