• 한국안전학회지
• /
• 제18권2호
• /
• pp.104-118
• /
• 2003

It has been criticized that conventional human reliability analysis (HRA) methodologies for probabilistic safety assessment (PSA) have been focused on the quantification of human error probability (HEP) without detailed analysis of human cognitive processes such as situation assessment or decision-making which are crticial to successful response to emergency situations. This paper introduces a new human reliability analysis (HRA) methodology, AGAPE-ET (A guidance And Procedure for Human Error Analysis for Emergency Tasks), focused on the qualitative error analysis of emergency tasks from the viewpoint of the performance of human cognitive function. The AGAPE-ET method is based on the simplified cognitive model and a taxonomy of influencing factors. By each cognitive function, error causes or error-likely situations have been identified considering the characteristics of the performance of each cognitive function and influencing mechanism of PIFs on the cognitive function. Then, overall human error analysis process is designed considering the cognitive demand of the required task. The application to an emergency task shows that the proposed method is useful to identify task vulnerabilities associated with the performance of emergency tasks.

• 한국산학기술학회논문지
• /
• 제15권2호
• /
• pp.979-988
• /
• 2014

본 연구는 간호사들이 인식한 안전 분위기와 업무환경을 포함한 조직의 특성과 투약오류보고장애요인간의 관련성을 검증하기 위한 연구이다. 수정된 안전 분위기, 업무환경, 투약오류보고장애 문항을 활용하여 7개 병원의 334명의 간호사들을 대상으로 하여 조사하였다. 자료수집기간은 2012년 9월 한달 간이었고, 서술적 통계, Pearson correlation coefficient, canonical correlation을 적용하였다. 조직의 특성은 투약오류보고장애와 세 가지 유의한 상관이 있었다. 첫 번째 정준상관계수는 .50(Wilks' ${\lambda}$=0.61, df=32, p<.001)이었고, 두 번째는 .35(Wilks' ${\lambda}$=0.81, df=21, p<.001), 세 번째는 .22(Wilks' ${\lambda}$=0.93, df=12, p=.018)이었다. 첫 번째 정준상관은 높은 안전 분위기와 업무환경이 오류보고에의 두려움을 제외한 투약오류보고와 관련이 있었다. 두 번째 식은 '의료인간의 안전 분위기'의 높은 지각과 높은 '병원에의 간호사 참여'와 '인적 자원의 적절성'은 낮은 '불안감'과 '행정자들의 반응'과 관련이 있었다. 투약오류보고장애를 위한 전략과 안전 분위기와 업무환경과 같은 조직의 특성의 진보가 적용되어야 한다.

• 한국자동차공학회논문집
• /
• 제5권1호
• /
• pp.69-78
• /
• 1997

Main sources of the vibration in gear driving system are transmission error and backlash. Transmission error is the difference of the rotation between driving and driven gear due to tooth deformation and profile error. Vibro-impacts induced by backlash between meshing gears lead to excessive vibration and noise in many geared rotation systems. Nonlinear dynamic characteristics of the gear driving system due to transmi- ssion error and backlash are investigated. Transmission error is calculated for spur gear. Nonlinear equation of motion for the gear driving system is developed with the calculated transmission error and backlash. Numerical analysis of the equation and the experimental results show the existence of meshing frequency, superharmonic compon- ents. Instability of the gear driving motion is found on the basis of Mathieu equation. Rattle vibration due to backlash is also discussed on the basis if nonlinear jump phenomenon.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.773-776
• /
• 2005

In this paper, For improving the positioning accuracy of hydrostatic table, relationship between temperature of atmosphere and thermal characteristics of hydrostatic table is analyzed, and influence of thermal characteristics on positioning accuracy is also analyzed experimentally. From the experimental results, it is confirmed that positioning error and repeatability is $0.21{\mu}m\;and\;0.18{\mu}m$ when the laser scale which has $0.01{\mu}m$ of resolution is used as feed-back unit. and also confirmed that thermal deformation of scale and supporter, which occurs by the temperature variation of atmosphere, works as limit of repeatability in long time operation.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.359-362
• /
• 2003

The aerostatic stage. which is used in semiconductor process, is demanded higher velocity and more precise accuracy for higher productivity and integrated performance. So, in the case of XY stage, H type structure, which is designed two co-linear axis of guide-way, driving force in one surface, has advantage of velocity and accuracy compared to conventional tacked type XY stage. To analyze characteristics of H type aerostatic stage, H type aerostatic surface XY stage is made, which is driven by linear motor and detected position with precise optical linear scale. And, analyze characteristics of motion error, effect of angular motion on positioning accuracy error and effect of simultaneous control on variation of velocity.

• 환경정책연구
• /
• 제3권2호
• /
• pp.89-112
• /
• 2004

This Study aims to demonstrate how much flood vulnerability in urban area changed for the past 32 years by using the panel model. At the same time, this study strives to determine the primary factors and to construct an effective counter-plan by means of empirical research. After selecting research hypotheses based on considerations of issues concerning causes for urban flooding, their relevance is put to the test by conducting empirical research in individual case locations. This research verifies the four research hypotheses by using one-way error component regression model. In conclusion, this research has shown that urban land use and local characteristics act as significant flood determinants, with forests acting to reduce flood dangers. Moreover, constructing embankments can no longer represent a reliable flood control policy. The changes in future flood control policies need to incorporate local characteristics and to minimize natural destruction, so that humans and nature can coexist through environmentally friendly flood management policies.

• Journal of Communications and Networks
• /
• 제12권5호
• /
• pp.459-465
• /
• 2010

A new blind equalization algorithm that is based on maximizing the probability that the constant modulus errors concentrate near zero is proposed. The cost function of the proposed algorithm is to maximize the probability that the equalizer output power is equal to the constant modulus of the transmitted symbols. Two blind information-theoretic learning (ITL) algorithms based on constant modulus error signals are also introduced: One for minimizing the Euclidean probability density function distance and the other for minimizing the constant modulus error entropy. The relations between the algorithms and their characteristics are investigated, and their performance is compared and analyzed through simulations in multi-path channel environments. The proposed algorithm has a lower computational complexity and a faster convergence speed than the other ITL algorithms that are based on a constant modulus error. The error samples of the proposed blind algorithm exhibit more concentrated density functions and superior error rate performance in severe multi-path channel environments when compared with the other algorithms.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1995년도 추계학술대회 논문집
• /
• pp.803-806
• /
• 1995

The vibration and nosic of gears is causeed by manufacting error,alignment error in assembly, and thr meshing stiffness of gears which changes periodically as the meshing of teeth process. On a pair of power transmission helical gears with profile error, the relation between the characteristics of gear vibration and the profile error type have been investigated by simulating the vibrational acceleration level and calculating the natural frequency. The results show that the profile error decrease the natural frequency by reducing the tool stiffness and that the concave error type increase the vibrationsl level. And this paper describes the effect of the tip relief on the vibrational acceleration level which a pair of helical gears with concave error generates.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.934-939
• /
• 2004

This paper propose a study on the Feed Characteristics of Twist Friction Driver. We are using Twist Friction Driving mechanism system. The system consists of Twist Friction Driver elements such as driving shaft, driven roller, Spring for pre-load, Air bearing guide, Servo motor, and measuring devices such as Encoder of Servo motor, Laser interferometer, LVDT . The Twist Friction driver is mechanically simple and very quiet at high speed, and has low pre-load. So The Twist Friction driver can materialize an ultra precision feed-resolution. The feed characteristics of the driver is determined by slip and angular error, backlash.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 춘계학술대회 논문집
• /
• pp.676-680
• /
• 2000

In this paper, an extended volumetric error model considering backlash in a three-axis machine tool was proposed and utilized for calculating the volumetric error of the machine tool at any position in three-dimensional workspace. Backlashes are interrelated; i.e. the angular backlash affects the straightness errors which then affect the calculated squareness errors. Therefore, a new concept was introduced to define the backlash of squareness errors to incorporate the backlash of squareness error into the volumetric error, and the characteristics of the backlash of squareness error were investigated. The effects of backlash errors were assessed, by experiments, fur 21 geometric errors of a machine tool. The backlash error was shown to be one of the systematic errors of a machine tool. Based on this volumetric error model, a computer-aided volumetric error analysis system was developed for a three-axis machine tool in this paper. Then the volumetric error at an arbitrary position can be obtained, and displayed in a three-dimensional graphic form.