• Title/Summary/Keyword: displacement checking

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Kinematic Comparative Analysis of Short Turns between Skilled and Unskilled Alpine Skiers

  • Jo, Hyun Dai
    • Korean Journal of Applied Biomechanics
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    • v.29 no.4
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    • pp.219-226
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    • 2019
  • Objective: The purpose of this study is to provide a better understanding of short turn mechanism by describing short turns after kinematic analysis and provide skiers and winter sports instructors with data through which they are able to analyze right postures for turns in skiing in a systematic, rational and scientific manner. Method: For this, a mean difference of kinematic variables (ski-hip angle, ski-shoulder twist angle, pole checking angle, the center of gravity (CG) displacement, trunk forward lean angle) was verified against a total of 12 skiers (skilled and unskilled, 6 persons each), regarding motions from the up-start to down-end points for short turns. Results: There was no difference in a ski-hip twist angle. The ski-shoulder twist angle was large at the up-start point while a pole-checking angle was high at the down-end point in skilled skiers. Concerning the horizontal displacement of CG, skilled skiers were positioned on the right side at the upstart point. No significant difference was observed in the trunk forward lean angle. Conclusion: According to the ski-shoulder twist angle and CG horizontal displacement results, the upper body should be kept leant toward the pole. In addition, big turns should be made via edging and angulation. During pole checking, the hand holding the pole should be thrown and released toward a vector direction of the forearm.

A Study on Algorithm of Checking Errors in Assembly Process of Feed Drive system in NC Machine Tools (NC공작기계 이송기구의 조립시 발생하는 결함의 발견)

  • Park, Jong-Bong
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.2
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    • pp.141-147
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    • 2001
  • This paper presents a developing algorithm of checking errors of feed mechanism in the NC machine tool with DAC method. It is useful to check static and dynamic rigidity with relation between lost motion and current of rotor. For checking error of feed in assembly tuning with machining center proposed checking algorithm is useful.

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A Study on the Preference for Choosing an Automobiles according to the Demographic Characteristics (인구통계적 특성에 따른 자동차 선택의 선호도에 관한 연구)

  • Baek, Sung-Hyun;Chang, Kyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.30 no.1
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    • pp.25-32
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    • 2007
  • Automobile manufacturing companies should provide the products and service that can satisfy consumers who usually want various kinds of automobiles. This paper studied the relations among several demographic characteristics(gender, age, occupation, income) of consumers and automobile's attributes(engine performance, engine displacement, price, maintenance expenses, color, etc.) and preferred automobile(kind, size, company, price). For the relation research we established a model and related hypotheses and used a questionnaire survey, where 350 subjects were questioned. After the analysis, many statistically significant results are obtained : consumer's gender has relations with the preference for engine performance, engine displacement, price, color, and design; age has relations with the preference for engine displacement, maintenance expenses, free checking during A/S period, etc., occupation has relations with the preference for engine performance, engine displacement, price, maintenance expenses, fuel efficiency, etc. : income has relations with the preference for engine performance, engine displacement, price, maintenance expenses, mileage, reputation of car manufacturing companies, etc.; price and fuel efficiency has relations with the preference for car manufacturing companies. These results suggest the consumer-oriented sales of automobiles and are expected to be helpful for the effective strategy development of automobile marketing.

Flow and Pressure Ripple Characteristics of Hydrostatic Transmissions (유압전동장치의 유량 압력맥동 특성)

  • 김도태;윤인균
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.1
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    • pp.120-126
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    • 2001
  • This study deals with a flow and pressure ripple characteristics for a hydrostatic transmission(HST) consisting of a vari-able axial piston pump connected in an open loop to a fixed displacement axial piston motor. These flow ripples produced by pump and motor in HST interacts with the source impedances of the pump or motor and dynamic characteristics of the connected pipeline, and results in a pressure ripples, Pressure ripples. Pressure ripples in HSP is major source of vibration, which can lead to fatigue failure of components and cause noise. In this paper, the flow ripples generated by a swash plate type axial piston pump or motor in HST are measured by making use of hydraulic pipeline dynamics and the measured pressure data at two points along the pipeline. By using the self-checking functions, the validity of the method us investigated by comparison with the measured and estimated pressure ripples at the halfway section of the pipeline, and good agreement is achieved.

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Development of automatic surface grinder using PLC (PLC를 이용한 자동 연마석 평면 연삭기 개발)

  • 주해호;이재원;박현제
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.71-74
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    • 1992
  • This paper describes the automation of the surface grinder for a grinding wheel by application of programmable logic controller(PLC) with a position sensor, and a limit switch. The control system is designed to provide feeding a workpiece on the turn table and pressing it by the upper disk automatically. In this development the automation of checking the thickness of a grinding wheel is most important. In order to measure the relative displacement, the proximity sensors were employed and the sensitivities of the sensors were investicated and discussed the superiority. It has been shown by model experiment that the automation system of the surface grinder is performed satisfactory.

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Fragility based damage assesment in existing precast industrial buildings: A case study for Turkey

  • Senel, Sevket Murat;Kayhan, Ali Haydar
    • Structural Engineering and Mechanics
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    • v.34 no.1
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    • pp.39-60
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    • 2010
  • In Turkey, majority of industrial facilities are composed of precast buildings. However, precast buildings have suffered extensive damage during Kocaeli and Duzce (1999) and Adana-Ceyhan (1998) earthquakes. Therefore, in this study, fragilities of existing building stock and damage probabilities of precast buildings were studied. For this purpose, building inventories were prepared and variation of structural parameters was determined by investigating the design project of 65 precast buildings constructed in Denizli, Turkey. Twelve analysis models which reflect the stiffness, strength and ductility properties of building inventory were constructed. After the definition of strain based displacement limits and corresponding damage states for buildings, displacement demands were calculated by using non linear time history analysis. During the analyses 360 strong ground motion records were used. Exceedence ratios of concerned damage limits was calculated by checking the displacement demands and then PGV based fragility curves were constructed. Efficiency of strength, stiffness and ductility properties of existing precast buildings were investigated by comparing the fragility curves. The results have shown that the most effective parameters that govern the damage probabilities of precast buildings are stiffness and ductility. It was also stated that the results of fragility analysis and damage and failure observations performed after Kocaeli and Duzce Earthquakes are compatible.

Pitch Accent Realization in North Kyungsang Korean: Tonal Alignment as a Function of Nasal Position in Syllables

  • Sohn, Hyang-Sook
    • Phonetics and Speech Sciences
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    • v.3 no.2
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    • pp.37-52
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    • 2011
  • This study investigates patterns of the alignment of the accentual peaks in bisyllabic words of the CVNCV, CVNV, and CVNNV structures in North Kyungsang Korean. Based on the tonal alignment, patterns of the F0 pitch excursion are discussed relative to one another. Issues are addressed concerning how the tonal targets are aligned, and how the tonal specifications of nasals in postvocalic, intervocalic, and prevocalic environments are supplied in the LH, HL, and HH classes. Tonal specification of nasals in various environments is accounted for by extension of the L target, displacement of the pitch peak, and interpolation between two tonal targets, depending on the tonal class. The results in this study provide preliminary evidence that the categorical alignment of the tonal targets is implemented by simply checking the presence or absence of a nasal before or after the nucleus vowel on the segmental string, without reference to the constituency of the nasal in the syllable structure. However, the prosodic structure has a key role to play in explaining speaker-dependent variations in the tonal alignment. Sensitivity to tautosyllabicity has an effect on the shape of the F0 contour, and disparity in the patterns of the pitch excursion is represented as a function of syllable structure correlated with segmental composition of the nasal.

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Development of Displacement Measuring Sensor Module to Monitoring About Variation and Distortion for Bridge Infrastructure at Wireless Communication Environmental (교량구조물의 구조적 변형을 측정하는 무선통신기반 변위센서모듈 개발)

  • Ryu, Seung-Ki;Moon, Hak-Yong
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.5
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    • pp.87-95
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    • 2010
  • Lots of bridge structure generated the change of outward formation according to durability capability and decrepitude by long use. Especially, in case of the typhoon, snowing and earthquake is going to make rapidly more worse formation about the old structural facilitys. Also, outward formation by irregular and micro-distortion in bridge structure could not easily checked by normal diagnostics method. As a result, performance-capability of structure facility is getting to make a decline in standard of structure performance. Recently, real-time monitoring technology by wireless environment go into the study of irregular movement for structure facility. This paper presents the development of sensor to displacement checking about bridge structure. Sensing method of developed sensor put bring into the gyroscope technology using the acceleration speed and angular acceleration speed. This paper also will simulated to verified the monitoring capability of developed sensor against random vibration, frequency and distortion in simulated equipment.

A Case Study on the Field Monitoring of the Deep Rock Excavation Site in Urban Area (도심지 대심도 암반 굴착현장에서의 Face Mapping 적용사례)

  • Kim, Tae-Seob;Kim, Hyung-Min;Jo, Choong-Sick;Kang, Tae-Seong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1307-1316
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    • 2009
  • In this case, powerfulness quorum of destruction side which we have expected are supposed general limit value for rock floor when retaining of earth on the section of rock floor in the urban area. For digging in the urban area, there are a lot of dislocations to be disadvantage for safety of digging ants. The displacement of the pondside didn't converged with the phase of the excavation. Also, the speed of displacement got higher than the percentages of risk in the construction. So, we put into operation Face mapping for checking special quality of dislocations which appear on the digging ants. This results were used to decide a destruction in the case of the final excavation by analyzing with other results. It was possible to know the unstable distribution of a fault line in Face Mapping and to get powerful lens of a surface of discontinuity by tests indoors and outdoors. The results were also used to make a solution. Therefore, It's a successful example using the Partial TopDown for stable digging. And it is important that Face Mapping have to be practiced for solving the uncertainty of ground organization when digging design in the urban city.

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Evaluation of Seismic Performance for Bridge Using Capacity Spectrum Method (역량스펙트럼을 이용한 교량의 내진성능평가)

  • Park, Yeon-Soo;Choi, Sun-Min;Kin, Eung-Rok;Suh, Byoung-Chul
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.448-455
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    • 2007
  • In 1992, the first design standard of quake proof bridge was established. However, most bridge structures which were constructed without considering earthquake in former times need performance of quakeproof property. Quakeproof analysis in current bridges, is based on analysis of load base which just has strength over the load of simple structures but is not checked through simple comparison of strength performance of structures so that we would like to check that ADRS method is reasonable or not using ADRS method(Accleration-Displacement Response Spectrum Method), a analysis method based on displacement of object of performance test. As the result of that, the capacity spectrum method can avoid complex dynamic analysis in analysis based on loads and it efficiently applies to design verification with normal checking for quakeproof performance and aimed performance of new structures. However we can not consider effects of high modes and it has problem that does not consider falling of performance in structures by repeated load.

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