• Journal of The Korean Association For Science Education
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• v.43 no.1
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• pp.29-36
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• 2023

This study investigates the effects of the operation of science activity program on scientific literacy focusing on science cultural literacy and core competencies for pre-service teachers. 255 pre-service teachers of K University participated, and the effects of the program were examined through a paired-sample t-test with one group pretest-posttest design for science cultural literacy. Only the post-test was conducted on core competency growth perception, and differences in growth perceptions by competency were compared using ANOVA. As a result of the study, the average of pre-service teachers was higher than the pre-test for science culture literacy, and this difference was statistically significant (p<.05). In the core competency growth perception, 70.6% of pre-service teachers reported growth in scientific communication ability, and as a result of the post-hoc test using LSD, it shows statistically significant growth compared to other competencies (p<.05). Through this, it was possible to confirm the educational value of the science activity program as a way to develop pre-service teachers' scientific literacy.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.397-402
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• 2013

In super-tall building construction projects, schedule risk factors which vertically change and are not found in the low and middle-rise building construction influence duration of a project by vertical attribute; and it makes hard to estimate activity or overall duration of a construction project. However, the existing duration estimating methods, that are based on quantity and productivity assuming activities of the same work item have the same risk and duration regardless of operation space, are not able to consider the schedule risk factors which change by the altitude of operation space. Therefore, in order to advance accuracy of duration estimation of super-tall building projects, the degree of changes of these risk factors according to altitude should be analyzed and incorporated into a duration estimating method. This research proposes a simulation model using Monte Carlo method for estimating activity duration incorporating schedule risk factors by weather conditions in a super-tall building. The research process is as follows. Firstly, the schedule risk factors in super-tall building are identified through literature and expert reviews, and occurrence of non-working days at high altitude by weather condition is identified as one of the critical schedule risk factors. Secondly, a calculating method of the vertical distributions of the weather factors such as temperature and wind speed is analyzed through literature reviews. Then, a probability distribution of the weather factors is developed using the weather database of the past decade. Thirdly, a simulation model and algorithms for estimating non-working days and duration of each activity is developed using Monte-Carlo method. Finally, sensitivity analysis and a case study are carried out for the validation of the proposed model.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.273-276
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• 2020

Purpose: The purpose of this study was to investigate the effects of the resistance conditions on the electromyography (EMG) activity ratio of vastus medialis oblique (VMO) and vastus lateralis (VL) muscle during partial lunge exercise in healthy subjects in order to suggest the basic data of exercise intervention for such as patients with patellofemoral pain syndrome (PFPS). Methods: The participants of this study were healthy twenty two people with no knee pain, limitation of motion and past history of operation at lower extremity. The participants performed three types of lunge 1) no resistance, 2) anterolateral 45° resistance and 3) lateral 90° respectively. The EMG activity of the VMO and VL were recorded by surface EMG and the measured data normalized by the %MVIC value was analyzed by repeated measured ANOVA. Results: The results showed that the VMO/VL EMG activity ratio during lunge with anterolateral 45° resistance was significantly higher than with no resistance and lateral 90° resistance (p<0.05). There was no significant difference in VMO, VL, and VMO/VL muscle activity between male and female subjects (p>0.05). Conclusion: This study suggests that partial lunge exercise with anterolateral 45° resistance can increase the VMO/VL muscle activity in healthy subjects. This result could be used as basic data to develop therapeutic exercise programs such as PFPS patients.

• Korean Management Science Review
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• v.30 no.1
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• pp.15-24
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• 2013

We consider the single machine scheduling problem with a rate-modifying activity and time-dependent deterioration after the activity. The class of scheduling problems with rate-modifying activities and the class of scheduling problems with time-dependent processing times have been studied independently. However, the integration of these classes is motivated by human operators of tasks who has fatigue while carrying out the operation of a series of tasks. This situation is also applicable to machines that experience performance degradation over time due to mal-position or mal-alignment of jobs, abrasion of tools, and scraps of operations, etc. In this study, the integration of the two classes of scheduling problems is considered. We present a mathematical model to determine job-sequence and a position of a rate-modifying activity for the integration problem. Since the model is difficult to solve as the size of real problem being very large, we propose genetic algorithms. The performance of the algorithms are compared with optimal solutions with various problems.

• International Journal of Advanced Culture Technology
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• v.12 no.1
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• pp.34-42
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• 2024

This study investigated the academic achievement of science and high school students according to the characteristics of R&E activities in mathematics and science. In addition, based on the survey results, the correlation between R&E activity characteristics and mathematics and science academic achievement was studied through correlation analysis and factor analysis between subjects. There was a difference in academic achievement in mathematics and science according to the characteristics of the R&E activity area, and the experience of R&E activity was found to be closely related to the academic achievement of related subjects. Depending on the area of R&E activity, mathematical and scientific academic achievement was found to be two factors: mathematical logic and natural understanding. Natural understanding factors significantly influenced students' academic achievement in mathematics, physics, and life sciences, and mathematical logic factors significantly influenced the academic achievement of students in chemistry and earth science subjects. In particular, mathematical logic ability was concentrated in excellent physics class students, and natural understanding ability was concentrated in excellent life science class students. Since the characteristics of the R & E activity area greatly influence the academic achievement of mathematics and science, it will significantly contribute to the selection and operation of the R & E activity area of science high school students.

• Economic and Environmental Geology
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• v.32 no.3
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• pp.273-280
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• 1999

In order to protect inhabitans' health and to collect data for prediction of the effcts from accidental emission of rasioactive materials from nuclear power plant, exposed dose rate be monitored within the limit dose rate. This research was carried out to investigate the accumulation of environmental radioactivity around Younggwang Nuclear Power Plant, and to infer and in infer and assay the additional exposed dose rate of inhabitants in Younggwang site from the operation of nuclear plant operation. External radiation dose rate, radiation environmental samples, and exposed dose rate of inhabitants in Younggwang site were investigated for estimaing environment activity in the vicinity of the nuclear power plant area. For the external radiation dose rate, the result showed that range of normal variation was found and any artificial radioisotope was not deteted in the analysis of environmental samples. Exposed dose rate of inhabitants was lower than 0.4% of the limit value of ICRP and it may be concluded that there was no effect on inhabitants and environment from the operation of nuclear power plant.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.2
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• pp.102-106
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• 2003

This paper describes novel low-power high-speed flip-flop called dual edge-triggered NAND keeper flip-flop (DETNKFF). The flip-flop achieves substantial power reduction by incorporating dual edge-triggered operation and by eliminating redundant transitions. It also minimizes the data-to-output latency by reducing the height of transistor stack on the critical path. Moreover, DETNKFF allows negative setup time to provide useful attribute of soft clock edge by incorporating the pulse-triggered operation. The proposed flip-flop was designed using a $0.35{\;}\mutextrm{m}$ CMOS technology. The simulation results indicate that, for the typical input switching activity of 0.3, DETNKFF reduces power consumption by as much as 21 %. Latency is also improved by about 6 % as compared to the conventional flip-flop. The improvement of power-delay product is also as much as 25 %.

• Nuclear Engineering and Technology
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• v.39 no.6
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• pp.703-716
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• 2007

As digital and computer technologies have grown, human-machine interfaces (HMIs) have evolved. In safety-critical systems, especially in nuclear power plants (NPPs), HMIs are important for reducing operational costs, the number of necessary operators, and the probability of accident occurrence. Efforts have been made to improve main control room (MCR) interface design and to develop automated or decision support systems to ensure convenient operation and maintenance. In this paper, an integrated decision support system to aid operator cognitive processes is proposed for advanced MCRs of future NPPs. This work suggests the design concept of a decision support system which accounts for an operator's cognitive processes. The proposed system supports not only a particular task, but also the entire operation process based on a human cognitive process model. In this paper, the operator's operation processes are analyzed according to a human cognitive process model and appropriate support systems that support each cognitive process activity are suggested.

• Journal of Korean Academy of Nursing
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• v.41 no.4
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• pp.500-509
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• 2011

Purpose: Time-driven activity-based costing was applied to analyze the nursing activity cost and efficiency of a medical unit. Methods: Data were collected at a medical unit of a general hospital. Nursing activities were measured using a nursing activities inventory and classified as 6 domains using Easley-Storfjell Instrument. Descriptive statistics were used to identify general characteristics of the unit, nursing activities and activity time, and stochastic frontier model was adopted to estimate true activity time. Results: The average efficiency of the medical unit using theoretical resource capacity was 77%, however the efficiency using practical resource capacity was 96%. According to these results, the portion of non-added value time was estimated 23% and 4% each. The sums of total nursing activity costs were estimated 109,860,977 won in traditional activity-based costing and 84,427,126 won in time-driven activity-based costing. The difference in the two cost calculating methods was 25,433,851 won. Conclusion: These results indicate that the time-driven activity-based costing provides useful and more realistic information about the efficiency of unit operation compared to traditional activity-based costing. So time-driven activity-based costing is recommended as a performance evaluation framework for nursing departments based on cost management.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.47-51
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• 2013

Background: Postoperative complications after esophagectomy can lead to considerable patient discomfort and prolonged length of hospital stay. Lack of physical activity can be one of the independent risk factors for postoperative complications because physical activity is closely related to physical function. The objective of this study was to determine whether physical activity among esophageal cancer patients decreases their risk of postoperative complications after esophagectomy. Materials and Methods: We investigated 51 consecutive patients with newly diagnosed resectable esophageal cancer who were scheduled to receive esophagectomy between January 2009 and November 2011. Demographic, clinicopathologic, and treatment information were recorded and physical function was measured. The last 7-days short version of the International Physical Activity Questionnaire was used to assess physical activity before the operation. Stepwise multiple logistic regression analysis was used to determine whether preoperative physical activity is related to the risk of postoperative complications. Results: Male gender [OR 18.6, (95%CIs: 1.2-284.4); P=0.035], 3-field lymph node dissection (OR 9.6, [95%CIs: 1.4-66.6]; P=0.022), low-level physical activity (OR 28.3, [95%CIs: 3.5-227.7]; P=0.002), and preoperative comorbidities [OR 5.9, (95%CIs: 1.1-31.5); P=0.037] were found to be independently associated with postoperative complications. Conclusions: The present study shows that low-level physical activity, preoperative comorbidities, and 3-field lymph node dissection are independent and significant risk factors for postoperative complications after esophagectomy. Although further study is required, maintaining high-level physical activity preoperatively may decrease the risk of postoperative complications.