• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.233-236
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• 2002

This study was conducted to estimate the design flood by the determination of best fitting order for LH-moments of the annual maximum series at fifteen watersheds. Parameters of GEV distribution and flood flows of return period n years were derived by the methods of L, L1, L2, L3 and L4-moments. Frequency analysis of flood flow data generated by Monte Carlo simulation was performed by the methods of L, L1, L2, L3 and L4-moments using GEV distribution. Relative Root Mean Square Error (RRMSE), Relative Bias (RBIAS) and Relative Efficiency (RE) using methods of L, L1, L2, L3 and L4-moments for GEV distribution were computed and compared with those resulting from Monte Carlo simulation. At almost all of the watersheds, the more the order of LH-moments and the return periods increased, the more RE became, while the less RRMSE and RBIAS became. Consequently, design floods for the applied watersheds were derived by the methods of L3 and L4-moments among LH-moments in view of high confidence efficiency.

• Journal of the Korean Institute of Gas
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• v.3 no.1
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• pp.27-32
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• 1999

Chemical processes are highly nonlinear, multivariable systems and have complex structures. However, the controllability evaluation procedures are complicated, and the required information is very often unknown at the early design stage. Therefore, it is necessary to develop a procedure to evaluate and enhance controllability while designing processes and plants. To evaluate controllability in the design stage, it is most efficient to analyze process structure. Relative order can be used as a measure of 'physical closeness' between input and output variable. Structural controllability analysis using relative order is shown to be effective in a case study of heat exchanger network synthesis.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1055-1064
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• 2012

This research was to count and quantify relative importance through analytic hierarchy process on checkups items in order to solve the questions raised by uniformalized numbering in the established athletes self management test. This study has the following results. The relative importance in priority factors of the test is in following order of training management, mental care, body care and interpersonal management. It was also confirmed that relative importance varied according to every checkup item in the lower factors. Consequently, the new result from this study, as an initial research for the relative importance of athletes self management test, supplied the possibility in which the sports-field expert's opinion was reflected. It was expected that this study would be helpful for enhancing athletes' competence in the sports field.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.99-107
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• 2013

The purpose of this study is to examine the relative distances among English front vowels in a message produced by 47 Korean and American speakers in order to better instruct pronunciation skills of English vowels for Korean English learners. A Praat script was developed to collect the first and second formant values(F1 and F2) of eight words in each sound file which was recorded from an internet speech archive. Then, the Euclidean distances were measured between the three vowel pairs: [i-ɛ], [i-ɪ], and [ɛ-æ]. The first vowel pair [i-ɛ] was set as the reference from which the relative distances of the other two vowel pairs were measured in percent in order to compare the vowel sounds among speakers of different vocal tract lengths. Results show that F1 values of the front vowels produced by the Korean and American speakers increased from the high front vowel to the low front vowel wih differences among the groups. The Korean speakers generally produced the front vowels with smaller jaw openings than the American speakers did. Secondly, the relative distance of the high front vowel pair [i-ɪ] showed a significant difference between the Korean and American speakers while that of the low front vowel pair [ɛ-æ] showed a non-significant difference. Finally, the Korean speakers in the higher proficiency level produced front vowels with higher F1 values than those in the lower proficiency level. The author concluded that Korean speakers should produce the front high vowels distinctively by securing sufficient relative distance of the formant values. Further studies would be desirable to examine how strong the Korean speakers' English proficiency correlate with the relative distance of target words of comparable productions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.515-523
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• 2018

In order to obtain consistent change detection result for multi-temporal satellite images, preprocessing must be performed. In particular, the preprocessing related to the spectral values can be performed by the radiometric normalization, and relative radiometric normalization is generally utilized. However, most relative radiometric normalization methods assume a linear relationship between the two images, and nonlinear spectral characteristics such as phenological differences are not considered. Therefore, this study proposes a relative radiometric normalization which assumes nonlinear relationships that can perform compositive normalization of radiometric and phenological characteristics. The proposed method selects the subject and reference images, and then extracts the radiometric control set samples through the no-change method. In addition, spectral indexes as well as pixel values are extracted in order to consider sufficient information, and modeling of nonlinear relationships is performed through multilayer perceptron. Finally, the proposed method is compared with the conventional relative radiometric normalization methods, which shows that the proposed method is visually and quantitatively superior.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.10
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• pp.962-969
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• 2007

In this paper, an approach is developed for relative state estimation of satellite formation flying. To estimate relative states of two satellites, the Extended Kalman Filter Algorithm is adopted with the relative distance and speed between two satellites and attitude of satellite for measurements. Numerical simulations are conducted under two circumstances. The first one presents both chief and deputy satellites are orbiting a circular reference orbit around a perfectly spherical Earth model with no disturbing acceleration, in which the elementary relative orbital motion is taken into account. In reality, however, the Earth is not a perfect sphere, but rather an oblate spheroid, and both satellites are under the effect of $J_2$ geopotential disturbance, which causes the relative distance between two satellites to be on the gradual increase. A near-Earth orbit decays as a result of atmospheric drag. In order to remove the modeling error, the second scenario incorporates the effect of the $J_2$ geopotential force, and the atmospheric drag, and the eccentricity in satellite orbit are also considered.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1358-1366
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• 2006

In order to study the effects of shell contents on the liquefaction resistance of the shelly sand, NGI cyclic simple shear tests were performed for the shelly sands with shell contents of 0%, 5%, 10%, 20% and 30% under the effective vertical stress of 50kPa, 100kPa and 150kPa for 40% and 55% of relative density, respectively. Cyclic simple shear test results showed that for the low effective vertical stress, liquefaction resistance increased rapidly with the increase of shell contents in both 40% and 55% relative density. On the other hand, for the high effective vertical stress, the liquefaction resistance increased slightly in 40% relative density whereas the resistance was almost same in 55% relative density. Liquefaction resistance decreased with increasing effective vertical stress for both 40% and 55% relative density. In the same effective vertical stress and shell contents, liquefaction resistance increased with the increase of relative density of sands.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.169-177
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• 1997

This study aims at empirically clarifying the relationship between power and the interpersonal conflict, including nurses' understanding of their relative power, the causes of interpersonal conflicts with the nurses, and strategies to resolve conflicts, in order to understand how nurses' relative power affect their conflicts. For the empirical survey, the population was defined as all the nurses working at a medical organization in Seoul, Korea. 1083 nurses were selected as the sample for the questionnaire survey and statistical analyses. For the sampling, 32 medical organizations were selected by a stratified random method and sub-samples were arbitrarily drawn from each organization to obtain the final sample of 1083 nurses who responded to the questionnaire designed by the reseacher. According to the result of the study, most nurses experience conflict more than once a month, and 70.4% of the respondents answered that interpersonal conflicts were directly or indirectly caused by power relations. which indicates that they perceive power relations as the main cause of interpersonal conflicts. Nurses experienced the most conflicts with interns and residents(29.7%), then patients and their families(24.3%), higher-positioned nurses(12.3%), nurse colleagues(7.7%), lower-positioned nurses(6.5%), and staff doctors(5.1%). If we classify these into three groups. the frequency of the conflicts, from most frequent to least. is in the order of doctors. nurses, and patients. In terms of relative power, nurses perceive that they have greater power than patients and their families, lower-positioned nurses, and nurse colleagues. In contrast, nurses perceive that they have less power than interns and residents, higher-positioned nurses. and staff doctors. Among these groups. nurses perceive that they have the most power over patients and the least over staff doctors. These results indicate that nurses tend to experience more conflicts with members of groups that are stronger than themselves in terms of relative power, Nurses use positive strategies such as the compromise strategy(32.3%) or the collaboration strategy (20.3%) to manage conflicts, more than other strategies. However, they use avoidance or competition strategy more at the earlier stage, compromise strategy more in the mid stage, and collaboration strategy more at the later stage of the interpersonal conflict. In relation to power, nurses use the collaboration strategy or the compromise strategy more when their perceived power is greater than or equal to their counterpart's, and they use the avoidance strategy or the accommodation strategy if their power is less. In terms of source of power, nurses' perceived relative power is greater in the order of referent power. expert power, reward power, legitimate power. and coercive power. where referent power is perceived as having the greatest power and coercive power is least. Most nurses(69.3%) used their power to resolve a conflict. with positive outcomes. Expert power was used most frequently. Overall. this study strongly indicates that the enhancement of power of nurses to have equal power relations with doctors would heighten the success of conflict resolution, since power is the main cause of conflicts. Specifcally. nurses experience most conflicts with doctors against whom they perceive the greatest gap in power. and the choice of a conflict management strategy depend upon their power relations.

• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.69-81
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• 2001

The constitutive relation among capillary pressure, saturation and relative permeability should be predetermined in order to simulate immiscible water-gas flow in porous media. The relation between saturation and relative permeability becomes more important when the capillary force can be disregarded and viscous friction force governs the flow. In this study, a 2-dimensional finite difference numerical model was developed, in which the variation of viscosity with pressure and that of relative permeability with water saturation can be treated. Seven cases of parallel plate tests were performed in order to obtain the characteristic equation of relative permeability which would be used in. the developed numerical model. It was not possible, however, to match the curves of relative permeability from the plate tests with the existing emperical models. Consequently a logistic equation was proposed as a new emperical model. As this model was composed of the parameter involving aperture size, any aperture size of fracture can be applied to the model. For the purpose of verification, the characteristic equation of relative permeability was applied to the developed numerical model and the computed results were compared with those of plate test. As a result of application of numerical model, in order to check the field applicability, to single fracture surrounding an underground storage cavern, the simultaneous flow of water and propane gas was able to be simulated properly by the model.

• Journal of Korean Society for Quality Management
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• v.37 no.3
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• pp.123-139
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• 2009

This study examines the relative efficiency of 34 local public medical centers in Korea. In order to concretely grasp the causes of inefficiency and suggest improvement solutions, the desirable set point was established based on the actual value which needs to be improved. As a result of analysis, we determined that output must be increased while input is held constant in order to improve effectiveness through the actual value and set point. Efficiency cannot be achieved if input is augmented solely to increase output. Also, to increase output, the medical centers need to improve their quality without increasing any input for customer visits and hospitalizations. Further, in order to strategically promote effectiveness and efficiency of local public medical centers, these medical centers must focus on input resource and patient interchange through the mutual cooperation with local private hospitals and university medical centers.