• 대한방사선기술학회지:방사선기술과학
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• 제5권1호
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• pp.63-70
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• 1982

In order to estimate characteristics and functions of multi hole focusing type collimator, the authors measured the sensitivity and resolution varing with the distance between the face of collimator and source by experimental study. The results obtained with this study are as follows. 1. In comparison with focal distance obtained fram sensitivity measurement of various multi hole focusing type collimator, collimator A, C, E was 10 cm and collimator B, D was 12 cm in focal distance. 2. In regard of resolution of collimators having 10 cm focal distance, collimator A showed the finest resolutions than any other collimator(C, E). 3. By comparison regarding sensitivity by focal dist ante, the shorter the distance than a give focal distance of collimator, the worse the sensitivity of collimator. 4. With regard to resolution by focal distance, the shorter the distance than a given focal distance of collimator, the worse the resolution of collimator.

• Advances in concrete construction
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• 제8권4호
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• pp.277-283
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• 2019

In evaluating explosion-protection capacity, safety distance is broadly accepted as the distance at which detonation of a given explosive causes acceptable structural damage. Safety distance can be calculated based on structural response under blast loading and damage criteria. For the applicability of the safety distance, the minimum required stand-off distance should be given when the explosive size is assumed. However, because of the nature of structures, structural details and material characteristics differ, which requires sensitivity analysis of the safety distance. This study examines the safety-distance sensitivity from structural and material property variations. For the safety-distance calculation, a blast analysis module based on the Kingery and Bulmash formula, a structural response module based on a Single Degree of Freedom model, and damage criteria based on a support rotation angle were prepared. Sensitivity analysis was conducted for the Reinforced Concrete one-way slab with different thicknesses, reinforcement ratios, reinforcement yield strengths, and concrete compressive strengths. It was shown that slab thickness has the most significant influence on both inertial force and flexure resistance, but the compressive strength of the concrete is not relevant.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.60-61
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• 2006

An unwanted trip of backup distance relays often lead to a blackout. This paper presents investigation report on involvement of backup distance relays in the past blackouts and sensitivity-factor based algorithm to make a distinction between a fault and overload caused by line tripping. A preliminary idea to prevent deterioration of the situation due to unwanted trip of distance relays by utilizing the proposed algorithm is presented.

• 한국환경과학회지
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• 제28권9호
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• pp.737-749
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• 2019

In this study, the sensitivity analysis of hydraulic conductivity and separation distance (distance between injection well and pumping well) was analyzed by establishing a conceptual model considering the hydrogeologic characteristics of facility agricultural complex in Korea. In the conceptual model, natural characteristics (topography and geology, precipitation, hydraulic conductivity, etc.) and artificial characteristics (separation distance from injection well to pumping well, injection rate and pumping rate, etc.) is entered, and sensitivity analysis was performed 12 scenarios using a combination of hydraulic conductivity ($10^{-1}cm/sec$, $10^{-2}cm/sec$, $10^{-3}cm/sec$, $10^{-4}cm/sec$) and separation distance (10 m, 50 m, 100 m). Groundwater drawdown at the monitoring well was increased as the hydraulic conductivity decreased and the separation distance increased. From the regression analysis of groundwater drawdown as a hydraulic conductivity at the same separation distance, it was found that the groundwater level fluctuation of artificial recharge aquifer was dominantly influenced by hydraulic conductivity. In the condition that the hydraulic conductivity of artificial recharge aquifer was $10^{-2}cm/sec$ or more, the radius of influence of groundwater level was within 20 m, but In the condition that the hydraulic conductivity is $10^{-3}cm/sec$ or less, it is confirmed that the radius of influence of groundwater increases sharply as the separation distance increases.

• 대한의용생체공학회:의공학회지
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• 제30권4호
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• pp.341-346
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• 2009

Cutaneous electrogastrography is the measurement of electrical activity of the stomach on the abdominal surface. The validity of cutaneous electrogastrography is dependent upon the quality of the recording technique. The locations of electrodes are an important issue. We examined the influences of the inter-electrode distance of bipolar leads on electrogastrography measurements. The sensitivity distributions of EGG leads were calculated based on a 2D body fat model and evaluated according to the region of interest sensitivity ratio (ROISR). We simulated the ROISR of the inter-electrode distance in relation to various body fat thicknesses. The distance between the electrodes was proportional to the distance between the ROI and the surface of the abdomen. The results imply that inter-electrode distance can be applied in electrogastrography according to human body fat thickness.

• 한국광학회지
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• 제27권2호
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• pp.67-72
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• 2016

영사식 무아레 토포그래피에서 실제 물체에 대한 측정오차를 줄이기 위해서는 물체높이에 따른 무늬차수의 변화율인 무늬 민감도에 대한 조사가 필수적이며, 또한 무늬 민감도를 활용을 하면 절대 차수 결정이 매우 편리하고 정확해진다. 영사기를 사용한 영사식 무아레 토포그래피에서 무늬차수를 결정하기 위한 변수는 광원의 위치와 물체의 위치, 격자주기이다. 이 변수들 중에서 광원의 위치를 횡축으로 움직이는 광원 횡축 이동법과 물체를 종축으로 움직인 물체 종축 이동법에 따른 무늬 민감도를 격자주기에 따라 서로 비교하고 이를 분석하였다. 그 결과 광원 횡축 이동법에서 광원과 상검출기 사이의 간격이 클수록 민감도가 높았으나, 물체 종축 이동법에서 물체와 결상렌즈 사이의 거리가 작을수록 민감도가 높았다. 그리고 두 방법에서 격자주기가 작을수록 민감도가 더 높았으며 변수 변화에 따른 무늬 민감도 변화량은 더 컸다.

• 한국환경과학회지
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• 제9권1호
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• pp.57-64
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• 2000

The sensitivity analysis of two short-term models (ISCST3, INPUFF2.5) is performed to improve the model accuracy. It appears that the sensitivities on the changes of wind speed, stack height and stack inner diameter in the near distance from source, stability and mixing height in the remote distance form source, are significant. Also the gas exit velocity, stack inner diameter, gas temperature and air temperature which affect the plume rise have some effects on the concentration values of each model within the downwind distance where final plume rise is determined. And in modeling for the atmospheric dispersion of point pollutant source INPUFF2.5 can calculate amount, trajectory of puff and concentration versus time at each receptors. So, it is compatible to analyze distribution of point pollutants concentration at modeling area.

• 대한기계학회논문집A
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• 제29권9호
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• pp.1217-1224
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• 2005

To improve the accuracy of a metamodel, additional sample points can be selected by using a specified criterion, which is often called sequential sampling approach. Sequential sampling approach requires small computational cost compared to one-stage optimal sampling. It is also capable of monitoring the process of metamodeling by means of identifying an important design region for approximation and further refining the fidelity in the region. However, the existing critertia such as mean squared error, entropy and maximin distance essentially depend on the distance between previous selected sample points. Therefore, although sufficient sample points are selected, these sequential sampling strategies cannot guarantee the accuracy of metamodel in the nearby optimum points. This is because criteria of the existing sequential sampling approaches are inefficient to approximate extremum and inflection points of original model. In this research, new sequential sampling approach using the sensitivity of metamodel is proposed to reflect the response. Various functions that can represent a variety of features of engineering problems are used to validate the sensitivity approach. In addition to both root mean squared error and maximum error, the error of metamodel at optimum points is tested to access the superiority of the proposed approach. That is, optimum solutions to minimization of metamodel obtained from the proposed approach are compared with those of true functions. For comparison, both mean squared error approach and maximin distance approach are also examined.

• 한국의류학회지
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• 제42권2호
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• pp.327-341
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• 2018

This study analyzed the influence of social distance and visual information on consumers' fashion style preferences in terms of information characteristics and providers. Data were collected from 521 females in their twenties and thirties who had experience using SNS. The empirical study results were as follows. First, with other factors of exposure under control, the social distance of information characteristics and providers showed a significant impact on fashion style preferences only when social distances were close. Second, the impact of social distance varied depending on the consumer's characteristics. This proved that innovation had significant negative influences, while conformity and informational sensitivity to others showed positive influences on the effects of social distance in terms of information characteristics. Innovation and fashion leadership also showed a negative influence on the social distance effect in terms of information providers. Third, conformity, informational sensitivity to others, and fashion leadership, proved to have a significant impact on the acceptance of eWOM in fashion styles, but innovativeness and normative sensitivity to others did not have a significant influence. This study can be used as baseline data in SNS marketing strategies for vitalizing information spread through eWOM.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권1호
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• pp.30-37
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• 2005

We present an air bridge type electrode system with tunable electrode distance for detecting electroactive biomolecules. It is known that the narrower gap between electrode fingers, the higher sensitivity in IDA (interdigitated array) electrode. In previous researches on IDA electrode, narrower patterning required much precise and expensive equipment as the gap goes down to nanometer scale. In this paper, an improved method is suggested to replace nano gap pattering with downsizing electrode distance and showed that the patterning can be replaced by thickness control using metal deposition methods, such as electroplating or metal sputtering. The air bridge type electrode was completed by the following procedures: gold patterning for lower electrode, copper electroplating, gold deposition for upper electrode, photoresist patterning for gold film support, and copper etching for space formation. The thickness of copper electroplating is the distance between upper and lower electrodes. Because the growth rate of electroplating is $0.5{\mu}m\;min^{-1}$, the distance is tunable up to hundreds of nanometers. Completed electrodes on the same wafer had $5{\mu}m$ electrode distance. The gaps between fingers are 10, 20, 30, and $40{\mu}m$ and the widths of fingers are 10, 20, 30, 40, and $50{\mu}m$. The air bridge type electrode system showed better sensitivity than planar electrode.