• Journal of The Korean Association For Science Education
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• v.25 no.7
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• pp.746-753
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• 2005

In order to be efficient teachers should understand the current level of leaners through diagnostic evaluation. However, it is arduous to administer a diagnostic examination in every class because of various limitations. This study examined, the major issues arising from the development of a new science diagnostic evaluation system by incorporating the using knowledge state analysis method. The proposed evaluation system was based on the knowledge state analysis method. Knowledge state analysis is a method where by a distinguished collection of knowledge uses the theory of knowledge space. The theory of knowledge space is very advantageous when analyzing knowledge in strong hierarchies like mathematics and science. It helps teaching plan through methodically analyzing a hierarchy viewpoint for students' knowledge structure. The theory can also enhance objective validity as well as support a considerable amount of data fast by using the computer. In addition, student understanding is improved through individualistic feedback. In this study, an evaluation instrument was developed that measured student learning outcome, which is unattainable from the existing method. The instrument was administered to pre-service physics teachers, and the results of student evaluation was analyzed using the theory of knowledge space. Following this, a revised diagnostic evaluation system for facilitating student individualized learning was constructed.

• Journal of Power Electronics
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• v.16 no.2
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• pp.717-730
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• 2016

The harmonic components of grid voltage result in oscillations of the calculated phase obtained via phase synchronization. This affects the security and stability of grid-connected converters. Moving average filter, delayed signal cancellation and their related harmonic elimination algorithms are major methods for such issues. However, all of the existing methods have their limitations in dealing with multiple harmonics issues. Furthermore, few studies have focused on a comparison and evaluation of these algorithms to achieve optimal algorithm selections in specific applications. In this paper, these algorithms are quantitatively analyzed based on the derived mathematical models. Moreover, an enhanced moving average filter and enhanced delayed signal cancellation algorithms, which are applicable for eliminating a group of selective harmonics with only one calculation block, are proposed. On this basis, both a comprehensive comparison and a quantitative evaluation of all of the aforementioned algorithms are made from several aspects, including response speed, required data storage size, sensitivity to sampling frequency, and elimination of random noise and harmonics. With the conclusions derived in this paper, better overall performance in terms of harmonic elimination can be achieved. In addition, experimental results under different conditions demonstrate the validity of this study.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1052-1060
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• 2018

Numerous studies suggest that the effects of lactic acid bacteria (LAB) on oxidative stress in vivo are correlated with their antioxidative activities in vitro; however, the relationship is still unclear and contradictory. The antioxidative activities of 27 Lactobacillus plantarum strains isolated from fermented foods were determined in terms of 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, and superoxide radical scavenging abilities, reducing activity, resistance to hydrogen peroxide, and ferrous chelating ability in vitro. Two fuzzy synthetic evaluation models, one with an analytic hierarchy process and one using entropy weight, were then used to evaluate the overall antioxidative abilities of these L. plantarum strains. Although there was some difference between the two models, the highest scoring strain (CCFM10), the middle scoring strain (CCFM242), and the lowest scoring strain (RS15-3) were obtained with both models. Examination of the antioxidative abilities of these three strains in $\text\tiny{D}$-galactose-induced oxidative stress mice demonstrated that their overall antioxidative abilities in vitro could reveal the abilities to alleviate oxidative stress in vivo. The current study suggests that assessment of overall antioxidative abilities with fuzzy synthetic models can guide the evaluation of probiotic antioxidants. It might be a more quick and effective method to evaluate the overall antioxidative abilities of LAB.

• Journal of Korea Water Resources Association
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• v.41 no.1
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• pp.87-100
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• 2008

The alternative evaluation index (AEI) is developed and applied to determine the priorities of some options for integrated watershed management. Based on the results of continuous simulation model, AEIs of some feasible alternatives are calculated using multicriteria decision making techniques and sustainability evaluation model, DPSIR (Drivers-Pressure-State-Impact-Response).

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1188-1195
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• 2014

This paper presents an analytical technique for reliability evaluation of electrical distribution network (EDN) containing distributed generation (DG). Based on hierarchical levels of circuit breaker controlling zones and feeder sections, a directed-relation-graph (DRG) for an END is formed to describe the hierarchical structure of the EDN. The reliability indices of EDN and load points can be evaluated directly using the formed DRG, and the reliability evaluation of an EDN containing DGs can also be done without re-forming the DRG. The proposed technique incorporates multi-state models of photovoltaic and diesel generations, as well as weather factors. The IEEE-RBTS Bus 6 EDN is used to validate the proposed technique; and a practical campus EDN containing DG was also analyzed using the proposed technique.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.150-155
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• 2002

En case of the fatigue life evaluation of rolling stock structures, mainly deterministic fatigue life evaluation has been carried out. But most of the parameters influencing on the fatigue life have a probabilistic distribution such as normal, log-normal, Weibull, etc. Therefore, to take probabilistic factors into fatigue life evaluation, probabilistic methods are being applied to the fatigue life evaluation of rolling stock. In this paper, probabilistic S-N analysis and methods using limit state functions are introduced. And some results of fatigue life evaluation obtained with these methods for rolling stock structures are shown.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.212-221
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• 2022

In this paper, the evaluation procedure applying the limit state design method is studied to be consistent with the newly issued bridge design code in Korea. The live load factor for evaluation is proposed by calibrating for the target reliability index through reliability analysis. Using the actual bridge information collected for the representative bridge types in Korea, the load effects of the design live loads for the previous and current design codes are calculated and compared. The live load factor is calibrated through reliability analysis using the minimum required strength which equals to the load effect obtained for the example bridge. Bridge evaluation is performed by applying the live load factors for the evaluation level as well as design level. The load rating result is generally increased by applying the limit state design method compared to the previous design method and applying the proposed load factor for lowered target reliability index further increased the rating result.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.2
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• pp.284-289
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• 2014

The experiment was conducted to evaluate the ingestive behavior of lambs confined in individual and group stalls. We used thirty-four lambs in their growing phase, aged an average of three months, with mean initial live weight of $17.8{\pm}5.2$ kg. They were allotted in a completely randomized design with 24 animals kept in individual stalls and 10 animals confined as a group. The experiment lasted for a total of 74 days, and the first 14 days were dedicated to the animals' adaption to the management, facilities and diets. The data collection period lasted 60 days, divided into three 20-d periods for the behavior evaluation. The animals were subjected to five days of visual observation during the experiment period, by the quantification of 24 h a day, with evaluations on the 15th day of each period and an interim evaluation consisting of two consecutive days on the 30th and 31st day of the experiment. The animals confined as a group consumed less (p<0.05) fiber. However, the animals confined individually spent less (p<0.05) time on feeding, rumination and chewing activities and longer in idleness. Therefore, the lower capacity of lambs confined in groups to select their food negatively affects their feeding behavior.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.167-172
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• 1998

Methods of evaluating the physiological activity of the living body are EEG, EOG, Heart rate, and Rectal temperature, etc. In the study of Hagiwara and Araki(1993), they found positive correlations among performance test, physiological measurement, and subjective feeling measurement. Human alertness of pilot directly influences on the flight performance that accomplishes a lot of vigilance task and procedure execution in flight. Accordingly, this paper deals with the quantitative and objective performance test based on tracking error and reaction time by means of the new computer test program into which the perception-motion system of human beings is applies. Throughout this experiment using performance thst, the results suggest that performance capability in state of sleep deprivation 2 hours and alcoholic 0.05 .apaprox. 0.06% in blood were more impaired than one in a normal state, and they further showed statistically significant differences between them, which were influenced by impairment factors of body regulation and pilot's grade. We also obtained the prediction value and the 95% confidence interval of tracking error and reaction time at the normal state for the purpose of distinguishing performance capability between the normal state and the abnormal state. And it is ecpected that the evaluation of human alertness using performance test will be applied to the quantitative assessment of an each pilot's realistic consciousness/attention, and will lead a flight commander to the accurate decision of mission approval prior to a flight.

• Journal of The Korean Association For Science Education
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• v.5 no.1
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• pp.63-79
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• 1985

The purpose of our survey study was to investigate the status on perception and actual state toward science educational evaluation and objectives of middle school science teachers in Pusan. The perception and actual state were surveyed by the questionaire which was developed by Jong-Ok Woo et. al. We developed two kinds of questionaire. One is designed to use Likert type scale and is composed of two main category(SE; Science educational evaluation, SO; Science educational objectives) which contains 21 question items, and the other has 16 question items From 313 science teacger's responses of 75 middle schools in pusan, the tendency. of total(SE+SO) and each sub category, and the contrast with their background and actual state were analized by SPSS program of KAIST. Some results of our survey study can be summarized as follows; 1. Total tendency of science educational evaluation(SE) and objectives(SO) of middle school science teachers in pusan shows a positive and right tendency of conception in general(m-85.8/100). 2. Tendency of SE(m-87.8/100) are slightly higher than SO(m-81.7/100). At the level of 5% significance, there are correlated but shows low correlation (r=0.12(4). 3. In each correlation toward total tendency(SE+SO), SE is highly correlated(r-0.8486) but SO is moderately correlated(r=0.6297) at the level of 0.1% significance. 4. Tendencies of 5sub category (PE, PC, PD, PO, PB) shows considerably right tendencies (m=$73.4/100{\sim}92.7/100$), there are moderately correlated foward total tendency(SE+SO) at the level of 0.1% significance (r=$0.49{\sim}0.60$). 5. At the level of 5%significance, total means are no differences which their background(Sex, Final alma mate, Major, Difference of training), but there is differences to teaching career at the level of 5% significance.