• Journal of Korean Elementary Science Education
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• v.36 no.3
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• pp.219-226
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• 2017

In this study, the reliability and validity of the retrospective pre-post test were analyzed in order to solve the problem of traditional pre-post test including response shift bias. Samples of the study were 162 elementary school students who are studying at the S university gifted education center in Seoul. Before completion of the field trip, we conducted pre test of science-related attitudes. After completion of the field trip, respondents were asked to compare their responses of pre and post science-related attitudes to quantitatively analyze the commonalities and differences of the two tests. To find out more characteristics, qualitative data such as daily records and interview were also gathered and analyzed. The major results of the study are as follows. First, for the paired t-test, there was no statistically significant difference between separate pre-test scores and retrospective pre-test. There was a very high correlation between the separate pre-test scores and the retrospective pre-test. Second, there were significant differences in all seven sub-factors of science-related attitudes between the retrospective pre-test and the post-test. Third, the separate pre-test scores showed a slightly higher tendency than the retrospective pre-test scores. This suggests that the response shift bias appears when it is performed the separate pre-test in affective domain. As a result of the interview, it was found that the evaluation standards of separate pre-test did not match with those of post-test. Forth, internal consistency reliability of the retrospective pre-test was higher than that of the separate pre-test. However, there were significant differences in six factors of science-related attitudes excluding the 'social implications of science' between the separate pre-test and the post-test. Based on these results, the retrospective pre-post test design provides simplicity and convenience to both respondents and investigators, as it is done with one test. The retrospective pre-post test design can be regarded as a valid design for the self-report measurement of affective domain on a single experimental group.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.16-23
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• 2012

This paper relates to a study on the economic of electrical storage device for supplying power in sunless days, in the stand alone PV/Wind hybrid system, which it is applied to separate houses. In a photovoltaic/wind hybrid power system used in a separate house, when only the battery is used in sunless days, the capacity of the battery is become larger. For example, as in recent days, if cloudy days are frequent due to anomaly climate, it is difficult to supply power stably by only the battery based upon pre-estimated sunless days. Accordingly, in order to supply stably power of new renewable energy such as solar to any separate houses, it is preferable to reduce the capacity of battery by decreasing the number of sunless days when estimating the capacity of battery and to drive the small generator for compensation of the power shortage.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.133.2-133
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• 2001

This paper focuses on the feasibility of fuzzy logic control for networked control systems. In order to evaluate its feasibility, a networked control system for motor speed control is implemented on a Profibus-DP network. The NCS consists of several independent, but interacting processes running on two separate stations. By using this NCS, the network delay is analyzed to find the cause of the delay. Furthermore, in order to prove the feasibility, the fuzzy logic controllers performance is compared with those of conventional PID controllers. Based on the experimental results, the fuzzy logic controller can be a viable choice for NCS due to its robustness against parameter uncertainty.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.82-90
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• 1998

The study was carried out to investigate on the response of environmental sanitation problems in action of the volume based waste charge system in Seoul. The responses from the 396 persons who dwelled in Seoul was stimulatively answered, this system was considered as a successful one 69.6% of total answers, but little portion (21.2%) of those was unknown on the mean of this system. And we knew that this system was need to the communication and education through the press media about this one. After the action of the volume based waste charge system, the volume of refuse discharged in a day was decreased 30-50% than before. In the problems of environmental sanitation after this system, the number of sanitary insect(cockroach etc) and rat was decreased, also the production of order and dust caused by refuse was decreased in comparison with those before. This results were considered that the Separate Collection should be perfectly performed. In response, the regular envelope of refuge was serious problems, the improvement for this one was demanded, The kind of difficult refuse treated was waste foodstuffs> electric products> rubbers> furniture> bottles, cans>papers, pulps etc. and the next proposal for this system should be prepared. Conclusively, the volume based waste charge system should be remarkable system in terms of resources recycling as well as wastes reduction. Above all in order to conform this system the separate collection system should be systematically performed, the next improvable proposal of the detailed methods in this system should be prepared.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.12
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• pp.3728-3740
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• 1996

High-quality cups of deep drawing ratio of more than four cannot be simply drawn by conventional drawing and redrawing processes. In the present study, after the first deep drawing process, subsequent hydromechanical reverse redrawing with controlled radial pressure is employed. In order to increase the deep drawing ratio up to muchmore than four, the radial pressure should be controlled independently of the chamber pressure and thus an optimum forming condition can be found easily by varying the radial pressure. The process has been subjected to finite element analysis by using the rigid-platic material modeling considering all the frictional conditions induced by the hydrostatic pressure. In order to consider the pressure effect on the sheet, the pressure distributions on the flange part and the side wall part are calculated mumerically from simplified Navier-stokes equation. The comparison of the computation with the experiment has shown that the finite element modeling can be conveniently emplyed for the design of the process with reliability from the viewpoint of formability.

• Asian Journal for Public Opinion Research
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• v.10 no.2
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• pp.123-146
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• 2022

This study aims to identify the effect of the relationship between human resources management (HRM) and total quality management (TQM) on improving employee performance. Several previous qualitative studies have stated that TQM and HRM are separate methods. This article describes a new method using a quantitative approach. This research is needed to fill the gap in the literature by empirically analyzing the relationship between HRM, TQM practices, and organizational performance. Data was collected quantitatively from 100 employees in Indonesia through questionnaires and online survey methods. The data collected were analyzed using structural equation modeling (SEM) with the Lisrel 8.5 system. TQM-oriented HRM is operationalized as a second-order latent variable measured by four factors (training, empowerment, teamwork, compensation). The findings support the validity of the TQM-oriented HRM model as a hierarchical, second-order latent construct and show a strong relationship with employee performance. The results of this study are different from previous studies, which showed that TQM and HRM are separate methods. The results of our research provide an academic and practical overview that TQM-oriented HRM can be used to help organizations build platforms for human resources policies aimed at improving employee performance.

• Korean Journal of Veterinary Service
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• v.22 no.4
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• pp.377-383
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• 1999

Polymorphonuclear (PMN) leucocytes are fundamental importance to the body's defense mechanism and play a major role in the local and systemic reactions to infectious disease. Investigation of the physiological and pathological role of the various leucocyte subtypes in host defence mechanisms is dependent upon the isolation of adequate numbers of viable, pure leucocyte fractions. This report describes the separate frequency of PMN leucocytes both from buffy coat layer and from packed RBC layer when bovine peripheral blood was treated with various anti-coagulants such as acid-citrate-dextrose(ACD), ethyldiaminetetraacetic acid(EDTA), sodium citrate and heparin. The separate frequencies of PMN leucocytes from buffy coat layer was 60.4$\pm$9.6%(heparin), 56.8$\pm$11.8%(sodium citrate), 30.6$\pm$14.1%(ACD) and 6.2$\pm$3.7%(EDTA), in order. Those from packed RBC layer monitored with EDTA, ACD, sodium citrate and heparin was 85.0$\pm$4.7%, 84.3$\pm$5.5%, 83.8$\pm$6.5% and 76.3$\pm$7.7%, respectively. The Ficoll-hypaque(FH) density gradient method was used to remove a small part of lymphocytes and/or monocytes from leucocytes in packed RBC layer. With the result that it increased separate frequency of PMN leucocytes from EDTA(89.9$\pm$2.4%), ACD(89.5$\pm$3.6%), and sodium citrate(83.6$\pm$10.3%) than heparin(68.4$\pm$13.9%). These results indicate that the use of EDTA and ACD as anticoagulant Is suitable for the separation of PMN leucocytes from bovine peripheral blood, and that the FH density gradient method is able to increase the separate frequency of PMN leucocytes from packed RBC layer.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.982-990
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• 2006

Generally CSOs (Combined Sewer Overflows) are regarded as one of the most serious nonpoint pollution source in the urban watershed, Particularly, the water quality of the Oncheon stream is seriously affected by CSOs because the capacity of interception sewer system connected to the Suyoung wastewater treatment plant is too small to intercept most storm water discharges. The objective of this study is to evaluate the effect of nonpoint source on an urban stream with regards to combined sewer system and separate sewer system using GIS (Geographic Information System) and SWMM (Storm Water Management Model), and to provide an insight for the management of urban stream water quality. In order to consider the effect of CSOs on the receiving water quality, the flow divider element in SWMM was applied. The model calibration and verification were performed by the measured data of quantity and quality on the Oncheon stream. The quantity data acquired from the Suyoung wastewater treatment plant were also used for this procedure. In case of separate sewer system, the modeling results showed the increased tendency in streamflow compared with the combined system in dry weather, In addition, the water quality is remarkably improved in rainfall events at the separate condition. The results imply that the construction of separate sewer system should be taken into first consideration to restore the quality and quantity of water in urban streams.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.171-178
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• 2021

A comparative study was conducted to examine the effects of mixed and separate gender feeding on growth performance of Korean native chickens (KNC) against a white semi-broiler (WSB) and a commercial broiler (CB) over five weeks. 576 chicks were used with eight birds per cage in a randomized complete block design with 18 replicates per breed. For the KNC lines, three groups of male (M), female (F) and mixed-gender (FM) were used. Fresh water and feed were supplied on an ad-libitum basis. Birds were fed a standard starter (d 1 - 22) and grower diet (d 23 - 35). Body weight (BW), feed intake, and shank length (SL) were measured weekly. From the BW and feed consumed data, the average daily feed intake (ADFI), average daily gain (ADG), and feed conversion ratio (FCR) were calculated. The commercial broiler showed higher performance (p < 0.05) for all the indices measured for the entire period. The CB group consumed more feed and were more feed-efficient thus grew faster. This group was followed by the white semi-broiler and the KNC, in order. An intra-breed comparison for KNCs revealed that the males showed better growth performance with longer SL (p < 0.05) compared to the female and mixed-gender groups. The results showed that other than the breed type, mixed and separate gender feeding impacted on the growth performance of the two lines of Korean native chickens. Males for both lines of KNC generally performed better for the parameters measured, as determined by a greater BW and reduced FCR.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.693-696
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• 2001

Ketoprofen racemate is very useful pharmaceutical intermediate, but the hardness of separation to each enantiomer is most a barrier to apply pharmaceutical industry. To overcome this difficulty, we would like to separate S-ketoprofen from ketoprofen racemate. To design suitable mobile phase, hexane and t-BME(tri-buthyl-methyle-ether) were used to elute peaks of ketoprofen racemate separately. When the ratio of hexane/t-BME/acetic acid was 60/40/0.1(%v/v), each component was separated successfully. In order to separate large amount of S-ketoprofen, sample concentration was increased from 100ppm to 2000ppm. In this case, resolution was decreased due to the overlapping of peaks(1.65${\rightarrow}$0.94).