• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.35-41
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• 1998

The workplace noise environment is composed of three basic elements : manufacturing (in a generic sense) facilities, office areas, and the community around the facility. Work must be done by all employees , and this involves communication within a variety of locations within the facility ; areas may be extremely noisy, moderately noisy, or quiet, such as an office. At the same time, the facility should not be annoying to the community. In this paper, the workplace environmental noise of office areas in power plant are studied. Turbine generator in power plant generates the noise of 90∼95 dB(A) in the frequency range of 1 kHz, which may cause occupational hearing loss. By abatement method which are made of isolation material and distance damping effect, about 29.5 dB(A) reduction has been obtained in office areas of the Power Plant . But, the workplace environmental noise of office areas in the power plant is not suited to office's purpose.

• Child Health Nursing Research
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• v.8 no.1
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• pp.86-96
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• 2002

The purpose of this study was to understand life experience of mother's abscence to the adolescent boys. Nine participants(7th-9th grades) were selected and interviewed intensively. Data were analyzed according to the methods of Colaizzi. Significant statements were extracted from data. From those significant statements, 37 themes, 15 clusters of themes and 5 categories were emerged. Fifteen cluster of themes formed 5 categories : Feeling loneliness, longing for mother and suppressing the painful feelings, sense of distance between toward father and friend, being pessimistic about the situation they face, and feeling envy. In this study the author described unique life experience of adolescent boys who are living with single father.

• Journal of the Korean earth science society
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• v.38 no.5
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• pp.333-344
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• 2017

We present the environmental dependence of the luminosity-size relation of galaxies in the local universe (z < 0.01) along with their dependence on galaxy morphology represented by five broad types (E, dEs, S0, Sp, and Irr). The environmental parameters we consider are the local background density and the group/cluster membership together with the clustercenteric distance for the Virgo cluster galaxies. We derive the regression coefficient (${\beta}$), i.e., the slope of the line representing the least-squares fitting to the data and the Pearson correlation coefficient (c.c.) representing the goodness of the least-squares fit along with the confidence interval from bootstrap resampling. We find no significant dependence of the luminosity-size relation on galaxy morphology. However, there is a weak dependence of the luminosity-size relations on the environment of galaxies, in the sense that galaxies in the low density environment have shallower slopes than galaxies in the high density regions except for elliptical galaxies that show an opposite trend.

• The Pure and Applied Mathematics
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• v.4 no.1
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• pp.97-104
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• 1997

The large deviations theorem of Cramer is extended to conditional probabilities in the following sense. Consider a random sample of pairs of random vectors and the sample means of each of the pairs. The probability that the first falls outside a certain convex set given that the second is fixed is shown to decrease with the sample size at an exponential rate which depends on the Kullback-Leibler distance between two distributions in an associated exponential familiy of distributions. Examples are given which include a method of computing the Bahadur exact slope for tests of certain composite hypotheses in exponential families.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.3-8
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• 2011

In April 2010, Japan Cabinet Office has published the first countermeasure report for severe flood disasters. This report showed various flood-disaster scenarios and factors that widened damages. One of important suggestions was to transmit precious information for long-distance evacuation. So far, local municipalities have made Flood Hazard Map to inform resident risk and evacuation. In this paper, cognition and effectiveness of a flood hazard map in the down ARAKAWA river Tokyo were measured by social questionnaire survey. In conclusion, there were 3 factors to effect validity of a flood hazard map. There were (1) commitment to their neighborhood organization, (2) experience of Kathleen typhoon in 1947 and (3) level of using targeted river. As results, a logical diagram about a flood hazard map perception was drawn and discussed from a view of community-based approach.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2643-2645
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• 2004

The underwater system autonomously is navigated by using the wireless communication system, which receives the control signal from surface ship. The study proposes the new media access control protocol for underwater vehicles network in the view of communication distance and as CSMA(Carrier Sense Multiple Access) for the existing networks is intended to communication network using the high speed media such as electric signal or microwave signal, and thus it may introduce the reduction in throughput when applying the protocols to underwater communication network.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.64-70
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• 1993

Serious injuries and deaths due to multi-jointed robot occur when a man mispercepts. especially during robot teaching and maintenance work. Since industrial robots often operate with unpredictable motion patterns, establishment of safe speed limit of robot arm is indispensable. An experimental emergency conditions were simulated with a multi-jointed robot. and response characteristics of human operators were measured. The result showed that failure type, robot arm axis. and robot arm speed had significant effects on human reaction time. The reaction time was slightly increased with robot arm speed. though it showed somewhat different pattern owing to failure type. Furthermore the reaction time to the axis which could flex or extend. acting on a workpiece directly. was fastest and its standard deviation was small. The robot arm speed limit securing a‘possible contact zone’based on overrun distance was about 25cm/sec. and in this sense the validity of safe speed limits suggested by many precedent researchers were discussed.

• Educational Technology International
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• v.22 no.2
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• pp.199-225
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• 2021

The aim of the current study was to suggest priorities needed to be considered by university instructors when designing online learning. Based on three types of interactions (learner-content, learner-instructor, and learner-learner interactions) for effective online learning (Moore, 1989), draft questionnaires representing each type of interaction were written. After examining content validity by two Ph.D. experts, the survey was constructed with an Importance-Performance Analysis (IPA) form. Data of 133 university instructors were collected online. Results showed that support for designing learner-learner interaction was the priority for improving online learning. In terms of learner-instructor interaction, instructors needed to provide social-emotional support to learners so that learners could have a sense of belonging. For learner-instructor interaction, supporting instructors to monitor the level of understanding was the most highly demanding strategy for online learning. Limitations and suggestions for further studies were discussed.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.316-321
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• 2008

As people are aging, there are changes about biological psychological sociological. For these reasons, it will arise that changing body size, decreasing power of body, shrinking of living, becoming dull the senses, and feeling alienation loneliness sense of distance about society. Many studies have been done to give residential space supporting older adults' living. Recently many ubiquitous technologies are being development and applied to residential space. The purpose of this study was to classified ubiquitous services by housing supporting concept and older people's physical, psychological and social characteristics and to identify needs for ubiquitous services by older adults. The researches developed a survey instrument and collected the data from 260 people in July to August, 2008 who were more than 40 years old. The results of this study found that residents' current needs and suggested ubiquitous services in future residential environment for older adults.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.193-196
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• 2002

The relativistic theory has not been properly taken up by the marine hydrodynamicists. To take on a relativistic view, we confine ourselves to a simple vector case of a wave train in spacetime, to be shown to represent a sound wave or a surface wave, and bring in an observer who is travelling on another platform. We are interested in relative position of each event on these two worldlines. It, then, will be shown that the velocity, the acceleration, the encounter frequency, the group velocity, and the time and the space distance between the wave and the observer on the worldlines should all be derivable in principle. This is interpreted to mean that we really have the relativistic events taking place with different values of time dilation in the sense of 'spacetime', and that the well-known ${\lceil}special Theory of Relativity{\rfloor}$ applies just as well in hydrodynamic waves.