• 한국소음진동공학회논문집
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• 제24권9호
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• pp.731-740
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• 2014

Occupants induced floor vertical vibrations may cause other occupant's annoyance and lead to social loss. To help control such floor vibrations, several criteria have been developed mostly based on human perception tests and floor vibration tests. Floor vibration is evaluated by comparison with criteria and vibration parameters of subject floor, such as frequency, damping ratio, acceleration value, vibration duration time and occurrence frequency. Three acceleration value parameters are used in criteria; peak acceleration, rms acceleration and VDV, when a floor vibration serviceability is evaluated. Meanwhile rms acceleration and peak acceleration are adopted as vibration limit value in criteria and researches of human perception for vibration. Occupants induced floor vibration is transient rather than steady state. However, rms acceleration is not reliable parameter for evaluating transient vibration. The objective of this study is to investigate the characters of human perception level according to acceleration value parameters for vibration induced by heel impacts and walking activities.

• 한국분무공학회지
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• 제18권3호
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• pp.132-139
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• 2013

Smoke emissions from light duty diesel vehicles were measured using light extinction method with the free acceleration test mode. The smoke emissions for each measurement cycle of the free acceleration method showed large variations according to driver's pedal pushing pattern. The smoke values for each measurement cycle initially increased and reach a peak value. Integration of the smoke emissions with time for each measurement cycle was performed to get a representative smoke value which was obtained by averaging the integrated results. Two kinds of integration time range were used. One is range over the whole measurement cycle of the free acceleration method. The other is only the acceleration range in the measurement cycle. Overall, variation of the representative smoke values obtained by the integration method was reduced comparing to the traditional representative smoke value which was obtained from a peak smoke value over the measurement cycle. Ten vehicles of the same model with 2.5 liter diesel engines, and seven vehicles of the same model with 2.7 liter diesel engines, were tested using the free acceleration test method.

• 산업경영시스템학회지
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• 제22권52호
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• pp.43-52
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• 1999

In this study, the vibration damping characteristics of the powered hand tools transmitted in hand-arm system were examined and compared. The types of powered tools for the experiment are general typed drill, impact drill, grinder, and wire brush. To analyze the characteristics of vibration damping, the magnitude of acceleration of vibration on X, Y, and Z direction at tool, hand, wrist, and the joint between forearm and upper arm were measured respectively. The results indicated that impact drill generated the highest value of acceleration of vibration among the four types of tools used in the experiments. The highest value of the amount of acceleration of vibration was found in the direction of Y. And the amount of acceleration of vibration was significantly affected by the type of tool, type of work, and pushing forces. As become the more distant from the tool, the smaller the amount of acceleration of vibration. Also, the bigger the pushing force at the tool, the higher the acceleration of vibration.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 추계 학술발표회 논문집
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• pp.61-71
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• 2002

Color-code imaging should be one of the best display tools for the quick perception of both damage area and its intensity, In this study we proposed the standard color code corresponding to maximum observed acceleration value. Since the acceleration value changes with frequency contents, we suggested to limit the frequency band less than 10Hz. The background considerations of this limitation, magnitude vs. dominant frequency, natural characteristics of artificial noises and the relationship between velocity and acceleration, were reviewed in detail. The standard of color code was assigned from 0.001%g to 20%g based on the possible earthquakes at Korean peninsula and the color imaging given by RGB value was shown to be very consistent, irrespective of hardware configuration.

• 천문학논총
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• 제30권2호
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• pp.381-383
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• 2015

MOdified Newtonian Dynamics (MOND) is an alternative to the dark matter paradigm. MOND asserts that when the magnitude of acceleration is smaller than the acceleration parameter $a_0$, the response of the system to gravity is stronger (larger acceleration) than the one given by Newtonian dynamics. The current value of $a_0$ is obtained mostly by observations of spiral galaxies (rotation curves and the Tully-Fisher relation). We attempt to estimate $a_0$ from the dynamics of elliptical galaxies. We seek elliptical galaxies that act as the lens of gravitational lensing systems and have velocity dispersion data available. We analysed 65 Einstein rings from the Sloan Len ACS survey (SLACS). The mass estimates from gravitation lensing and velocity dispersion agree well with each other, and are consistent with the estimates from population synthesis with a Salpeter IMF. The value of $a_0$ obtained from this analysis agrees with the current value.

• 소음진동
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• 제7권6호
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• pp.1025-1030
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• 1997

This paper introduces the experimental results of ride values assessed for several passenger cars. The experiment was conducted at four vehicles on two roads for three persons by measuring the acceleration in the 12-axis of human. The results include the comparison of the ride values, such as the component ride values, overall ride value, and seat effective amplitude transmissibiity. It is proved that acceleration between 1 and 15Hz is the most significant in evaluating the ride quality. The contribution of the acceleration in each measurement axis is quantified from the component ride value. SEAT value shows a relatively low sensitivity for the road condition and human mass.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.410-415
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• 2008

This paper presents review on human comfort criteria in major codes and standards for tall buildings. In general, human comfort criteria of tall buildings have been used by magnitude of wind-induced acceleration response. Two different indexes in determination of the magnitude have been used: the peak value which occurs during a period of time and the rms value averaged over this same period. These distinctive acceleration indexes are discussed in detail and each criterion is reviewed and compared. The distinctions arisen because of the different wave forms, or acceleration signatures are addressed. It is described that which index of acceleration should be adopted in establishment of Korean human comfort criteria. In addition, some arguments from a technical standpoint that favor the use of each index are presented.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.105-108
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• 2006

should be in This paper presents review on human comfort criteria in major codes and standards for tall buildings. In general, human comfort criteria of tall buildings have been used by magnitude of wind-induced acceleration response. Two different indexes in determination of the magnitude have been used: the peak value which occurs during a period of time and the rms value averaged over this same period. These distinctive acceleration indexes are discussed in detail and each criterium was reviewed and compared. The distinctions arisen because of the different wave forms, or acceleration signatures were addressed. It is described that which index of acceleration should be adopted in establishment of Korean human comfort criteria. In addition, some arguments from a technical standpoint that favor the use of each index are presented.

• 한국식품위생안전성학회지
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• 제18권4호
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• pp.218-223
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• 2003

대조구와 1.5%-인삼강정의 AV, POV 및 산패위 발생시기를 측정한 결과 가속저장과 실온저장 간의 관계는 다음과 같다. 1. AV의 가속저장과 실온저장의 관계를 살펴보면, 대조구의 경우 가속저장 시 0시간<4시간<8시간<12시간<16시간<20시간<24시간은 실온저장 시 각각 0개월<약 1.1개월<약 1.4개월<약 3.4개월<약 4.3개월<약 5.1개월<약 5.9개월이며, 1.5%-인삼처리구의 경우 가속 저장 시 0시간<4시간<8시간<12시단<16시간<20시간<24시간은 실온저장 시 각각 0개월<약 1.2개월<약 2.5개월<약 2.9개월<약 4.7개월<약 5.4개월<6개월로 이와 같이 증가 하는 것으로 나타났다. AV는 $60^{\circ}C$, RH 50%에서 대조구이 경우 가속저장 1시간이 실온저장 7일에, 1.5%-인삼처리구의 경우 1시간이 실온저장 7.5일에 해당되는 것으로 나타났다. 2. POV의 가속저장과 실온저장의 관계를 살펴보면, 대조구의 경우 가속저장 시 0시간<4시간<8시간<12시간<16시간<20시간<24시간은 실온저장 시 각각 0개월<약 1.3개월<약 2.2개월<약 3.4개월<약 5.2개월<약 5.7개월<6개월 이상이며, 1.5%-인삼처리구인 경우 가속정장 시 0시간<4시간<8시간<12시간<16시간<20시간<24시간은 실온저장 시 각각 0개월<약 1.0개월<약 2.0개월<약 2.7개월<약 4.5개월<약 5.7개월<6개월로 이와 같이 증가 하는 것으로 나타났다. POV는 $60^{\circ}C$, RH 50%에서 대조구의 경우 가속저장 1시간이 실온 저장 7.5일에, 1.5%-인삼처리구의 경우 1시간이 실온저장 7.7일에 해당되는 것으로 나타났다. 3. 저장기간 중 산패취 발생시기의 경우, 대조구는 가속저장과 실온저장 시 AV 및 POV의 저장안전시기와 유사한 시기에 산패취가 발생하였으나, 1.5%-인삼처리구의 경우 가속저장이 실온저장에 비해 약 1개월 정도 앞서 산패취가 발생하여 다소 차이를 보였다.

• Journal of Biosystems Engineering
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• 제8권2호
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• pp.1-10
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• 1983

The resulting characteristics of vibrations show different patterns for the various oscillating mechanisms. These vibrations causes troublesome operation problems for the operators and sometimes for the machines. Furthermore, in some cases the practical usage of this oscillating mechanism is constrained by its mechanical conditions. In this study, a balanced oscillating tillage tool with triple blades having different acting area was designed. The horizontal and vertical oscillating accelerations and draft power requirement due to the various travel speeds, lift angles, amplitudes and oscillating frequencies were investigated in a laboratory soil bin with a soil having invariable properties. The results obtained are summarized as follows: 1. Overall, the horizontal acceleration decreased as the oscillating frequency and amplitude decreased. But the increase in travel speed caused the decrease horizontal acceleration. The blade with the lift angle of $30^{\circ}$ exhibited the lowest value of horizontal acceleration among the blades tested. 2. For the vertical acceleration, the fluctuating trend of oscillating acceleration was similar to the trend of the horizontal acceleration. 3. The draft power requirement decreased as the amplitude and oscillating frequency increased. But the increase in travel speed caused the increase in draft power requirement. The blade with the lift angle of $10^{\circ}$ showed the lowest value of draft power requirement among the blades tested.