• Journal of Korean Academy of Nursing
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• v.29 no.2
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• pp.215-224
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• 1999

The study was conducted to centum the construct of individual perception and preference for work characteristics as personal factors influencing Korean nurses' job satisfaction. The subjects of the study were 231 nurses who are currently working in intensive care units and have been for a minimum of 6 months. The study used the Staff Perception and Preference Scale(Song et al., 1997) to measure the individual's perception and preference on the technical. practice. and management components of the ideal work environment. The Korean version of the Staff Perception and Preference Scale consists of 16 items on perception and 13 on preference with each item related on a scale from 1(not at all) to 4(a great deal). Psychometric testing revealed that the preference and perception scale is internally consistent with Chronbach's alphas of .83 for perception scale arid .80 for preference scale. The subscales of the perception and preference scale also showed acceptable reliability for the early stage of the development of the instruments with Chronbach alphas of .62-.76 and .69-.83 respectively. Criterion-related validity of the scale was tested by examining correlations with individual growth need that is conceptually close to individual preference. but not to individual perception. Individual growth need was significantly related to individual preference(r＝.63, p<.05), but the correlation with the perception scale was not significant. A separate factor analysis for the each of perception and preference scales was performed with a three-factor loading solution based on a previous study. The results on the staff perception scale confirmed with varimax rotation that the items were cleanly and strongly loaded on technique. practice and management components, which together explained 50.7% of the variance. The factor analysis on the staff preference scale also yielded a three factor solution that explained 56.7% of the variance. but items on technique and management components were loaded together. This phenomena may due to the current nursing delivery system in Korea where nurses never experience either shared governance nor case management, and as a results they may not be able to consider management roles as their potential extended roles. Therefore, more efforts should be given to enhance nurses' autonomy and decision making in the technique, practice and management components of their work environment. Meanwhile, there is a need for continuously confirming and developing tools for individual perception and preferences to effectively enhance job satisfaction among Korean nurses through innovative work environments.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.49-56
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• 2014

It is important to keep stable effluent water quality and minimize operation cost in biological wastewater treatment plant. However, the optimal operation is difficult because of the change of influent flow rate and concentrations, the nonlinear dynamics of microbiology growth rate and other environmental factors. Therefore, many wastewater treatment plants are operated for much more redundant oxygen or chemical dosing than the necessary. In this study, the optimal control scheme for dissolved oxygen (DO) is suggested to prevent over-aeration and the reduction of the electric cost in plant operation while maintaining the dissolved oxygen (DO) concentration for the metabolism of microorganisms in oxic reactor. For optimal control, The oxygen uptake rate (OUR) is realtime measured for the identification of influent characterization and the identification of microorganisms' oxygen requirement in oxic reactor. Optimal DO seT-Point needed for the microorganism is suggested based on real time measurement of oxygen uptake of microorganism and the control of air blower. Therefore, both stable effluent quality and minimization of electric cost are satisfied with a suggested optimal setpoint decision system by providing the necessary oxygen supply requirement to the microorganisms coping with the variations of influent loading.