• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.97-100
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• 1987

An improved hydrothermal unit commitment algorithm is proposed for the purpose of optimal operation of electric power system. Especially, Dynamic Programming Method which is main scheme of the algorithm is modified to assure the feasible solution all the time. The effectiveness of the algorithm has been demonstrated by applying to a sample system.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.45-53
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• 2004

In the summer, the irradiated solar heat gain through the roof has an effect on the thermal environment of the top floor units of apartment houses. This paper investigated the differences of the indoor air temperature and thermal comfort index between the top floor unit and the middle floor unit by measuring them at the sample houses. The purpose of this paper is to provide quantitative data about the irradiated solar heat gain during the summertime through the roof of an apartment house and these data to be the source to reevaluate the appropriate roof insulation efficiency. From this study, we obtained the brief results as follows. Indoor air temperature at the top floor unit is $1.2\sim2.2^{\circ}C$ higher than that of middle floor unit. The evaluation of the indoor thermal comfort index at each sample rooms reveals notable thermal differences between the two units. Top floor units need more cooling load during the summertime compared to middle floor units. Therefore, solutions to reduce solar Heat gain at top floor units to be considered.

• Clinical Endoscopy
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• v.57 no.4
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• pp.501-507
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• 2024

Background/Aims: Polyps greater than 30 mm are classified as "giants". Their endoscopic removal represents a technical challenge. The choice of the endoscopic removal technique is important because it provides a resection sample for precise histopathological staging. This is pivotal for diagnostic, prognostic, and management purposes. Methods: From a retrospective analysis, we obtained a sample of 38 giant polyps. Eighteen polypectomies were performed using the epinephrine volume reduction (EVR) method, nine polypectomies utilized endo-looping or clipping methods, and 11 patients underwent surgery. Results: We obtained en bloc resection with the EVR method in all cases; histology confirmed the correct indication for endoscopic resection in all cases. Moreover, no early or delayed complications were observed, and no patient required hospitalization. Using endo-looping or clipping methods, we observed advanced histology in 1/9 (11.1%) cases, while another patient (1/9, 11.1%) had delayed bleeding. Among patients who underwent surgery, 5/11 (45.5%) were deemed overtreated and three had post-surgical complications. Conclusions: We propose EVR as an alternative technique for giant polyp resection due to its safety, effectiveness, cost-efficiency, and the advantage of avoiding the need to postpone polypectomy to a later time. Further prospective studies might help improve this experience and enhance the technique.

• Asian Journal for Public Opinion Research
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• v.3 no.3
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• pp.111-130
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• 2016

Researchers have been perplexed by the issue of unit nonresponse since the beginning of practicing survey research and have been attentive to the causes that lead to the occurrence of unit nonresponse as well as the impact of unit nonresponse. However, because researchers have little to no information regarding unit nonrespondents, it is unlikely that they are able to examine the differences between participants and nonrespondents to estimate the loss of representativeness in the final sample compared with the target population. Therefore, the lack of information regarding the absentees complicates addressing the unit nonresponse bias in a satisfactory manner. Therefore, the purpose of this study was to determine the demographic characteristics and political attitudes of nonrespondents by relying on information provided by their spouses, which was obtained through a telephone survey conducted in Taiwan. It is found that demographic variables as well as political attitudes are related to the likelihood of an individual becoming a unit nonrespondent in telephone surveys.

• Korean journal of applied entomology
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• v.36 no.2
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• pp.150-155
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• 1997

Distribution of pine needle gall midge infestations was analyzed from data collected in young Japanese red pine stands during 1992, and 1995-1996 in Kangwon-do. No significant differences in percentages of infested needle pairs were found among trees and between terminal and lateral shoots within a tree. However, the mean percentages of infested needle pairs increased significantly from the lower crown to the upper. Percentages of infested needle pairs on sample units, consisting 1 terminal and 2 lateral shoots, in the midcrown were best predictors of whole-tree percentages than were other crown levels. Therefore, a sample unit consisting of 1 terminal shoot and 2 lateral shoots per branch were fixed from the midcrown level. Number of tree and sample unit combinations needed to estimate pine needle gall midge infestations with given two levels of precision were determined.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1424-1435
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• 2015

The purpose of this study was to investigate the recognition about 'problem solving and invention' unit in technology and home-economics subject. The study was carried out through questionnaire survey method. The sample of this study was 397 8th middle school students. The data was collected using questionnaires and analyzed by the descriptive statistics, t-test and one-way ANOVA. The result of this study was as follows: First, middle school students presented positive preferences toward 'problem solving and invention' unit. Second, middle school students recognized the necessity of this unit. Third, the level of difficulty for this unit of students was intermediate. Fifth, middle school students recognized that learning 'problem solving and invention' unit made them have more interest than before learning it.

• Journal of Korean Society of Forest Science
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• v.4 no.1
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• pp.26-29
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• 1965

1. The purpose of this study was to find out the best sampling form and sampling unit in forest survey. 2. The value of small sampling unit was over estimated in comparison with that of large sampling unit. 3. The value of circular form was over estimated in comparison with that of the others. 4. The smallest unit for estimation in area sampling were as follows. a) 0.06 ha. in the rectangular plot. b) 0.08 ha. in the square plot. c) 0.10 ha. in the circular plot. 5. Conclusion was as follows. The best sampling unit was 0.06 hectoare in the rectangular plot, which was most economic above all and gave preferable result for in the forest survey.

• Journal of Korean Academy of Nursing Administration
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• v.16 no.3
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• pp.240-249
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• 2010

Purpose: This study was to investigate intensive care unit (ICU) nurse's knowledge and nursing performance on the intensive care unit syndrome. Method: A survey questionnaire was administered to a convenience sample of 123 nurses in a university hospital. Data were collected from August 1st to August 25th, 2009. Data were analyzed using SPSS/WIN 12.0. Results: The mean score for knowledge and nursing performance were66.96 and 74.97 respectively. According to the general characteristics, there were significant differences in knowledge depending on marital status, education level and career length and in nursing performance depending on their age, education level and career length. The correlation between knowledge and nursing performance was a significant positive one. Conclusion: Comprehensive educational programs are needed to decrease accident rates related to ICU syndrome and to improve the health of ICU patients.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1506-1509
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• 1999

This paper presents a new economic dispatch algorithm to improve the unit commitment solution while guaranteeing the near optimal solution without reducing calculation speed. The conventional economic dispatch algorithms have the problem that it is not applicable to the unit commitment formulation due to the frequent on/off state changes of units during the unit commitment calculation. Therefore, piecewise linear iterative method have generally been used for economic dispatch algorithm for unit commitment. In that method, the approximation of the generator cost function makes it hard to obtain the optimal economic dispatch solution. In this case, the solution can be improved by introducing a inverse of the incremental cost function. The proposed method is tested with sample system. The results are compared with the conventional piecewise linear iterative method. It is shown that the proposed algorithm yields more accurate and economical solution without calculation speed reduction.

• Journal for History of Mathematics
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• v.16 no.2
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• pp.71-86
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• 2003

Mathematics becomes more indispensible course today, while it seems approaching to the middle school students as a boring and hard one. So, we need to take more motivational teaching devices as well as mere emphases on its importance in order to keep the students up to tile curriculum and improve the education efficiency. Then, history of mathematics call lie one major source of the motivation, since, by telling the tales on the specific unit subject, teachers can awake the students'interest naturally. Today, most of the mathematics textbooks for the middle school students have some historical tales about each unit subject in their respective unit introduction. However, many tales don't seem quite helpful or motivating to understand unit subjects, for they are either abstract or fragmental. In that sense, this paper has three sample guidelines for teaching, which ate meant to introduce historical tales to motivate the students before teachers may get into tile main unit subject. Those suggested in this paper may work as the motivational teaching devices which would make the students mote interested, more positive, and consequently more successful in mathematics.