• Animal Bioscience
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• v.34 no.11
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• pp.1749-1756
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• 2021

Objective: Microminipig (MMP) is a miniature pig with an extra small body size for experimental use. In the present study, the occurrence of stillbirths and their genetic association with swine leukocyte antigen (SLA) class II haplotypes were evaluated in a population of MMPs. Methods: The occurrences of stillbirth and genetic association with SLA class II haplotypes using 483 stillborn and 2,246 live piglets, and their parents were compared among the three groups of newborn piglet litters; an all stillborn (AS) group consisting of only stillborn piglet litters, a partial stillborn (PS) group consisting of stillborn and live piglet litters, and an all alive (AA) group consisting of only live piglet litters. Results: The incidence of stillborn piglets was 483/2,729 (17.7%). Distributions of litter sizes, numbers of stillborn piglets in a litter, parities, and gestation periods were distinct among the three groups. The frequencies of low resolution haplotype (Lr)-0.7 or Lr-0.23 were higher in the AS group than in the PS or AA groups. In sires, the frequency of Lr-0.7 associated with the AS group was significantly higher in the AS group than with the AA group. In dams, the frequency of Lr-0.23 was significantly higher in the AS group than in the PS or AA groups, whereas the frequency of Lr-0.7 was not significantly different. Conclusion: The incidence of stillborn piglets in MMPs appears to be higher than those in other pig breeds. Several traits related with stillbirths such as the number of stillborn piglets and parities of the AS group were different from those of the PS and AA groups. Specific SLA class II haplotypes were associated significantly with a high incidence of stillbirths and could be used as genetic markers to adopt breeding strategies to lower the rate of stillbirth in MMPs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.90-99
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• 2020

The "Low Emission Zone" (LEZ) system restricts entry of vehicles with high air pollutants into city centers. Implementation of the system improves air environment around the world. Since 2012, operating restrictions have been applied to all of Seoul's metropolitan areas and some other metropolitan areas in the state. Beginning in December 2019, entry of 5th class vehicles to the central green transport zone of Seoul has been restricted. In this study we examine the status of operational restrictions in this zone, and predict the amount of traffic reduction expected when numbers of target vehicles are expanded in the future, we use data for each vehicle's emission grade: by region and 'Origin-Destination Traffic Volume'. After estimating the amount of traffic entering Seoul's 25 autonomous districts, by emission class, we propose a target region that may have a significant effect if target areas for automobile operation restrictions expand in the future.

• Journal of Korean Elementary Science Education
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• v.28 no.3
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• pp.292-303
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• 2009

In this study, we investigated the characteristics of the analogies, the mapping understanding, and the mapping errors on saturated solution of scientifically-gifted and general elementary students. Fifth graders (n=60) at four scientifically-gifted education institutes in Seoul and/or Gyeonggi province and fifth graders (n=91) at three elementary schools in Seoul were selected and assigned to the scientifically-gifted group and the general group respectively. After the students of each group performed the experiment and were taught about the target concept in the first class, they administered the test on the self-generating analogies on the target concept in the second class. The results revealed that the students in the scientifically-gifted group made more analogies, especially verbal/pictorial, structural/functional, enriched, and higher systematic ones, and had deeper understanding of the analogy than those in the general group. The numbers of the shared attributes included in the student-generated analogies and the scores of the mapping understanding of the students in the scientifically-gifted group were significantly higher than those in the general group. The students in the scientifically-gifted group had fewer mapping errors than those in the general group. However, not a few students in the scientifically-gifted group had at least one mapping error. Educational implications of these findings are discussed.

• The Journal of Korean Association of Computer Education
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• v.5 no.4
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• pp.99-109
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• 2002

The purpose of the research undertaken for this paper was to demonstrate the effects of WBI on students' achievement and their reactions. WBI was adapted for use on the lesson Theme of Poems in Korean textbook for Middle School second graders. Hypothesis 1 was that there would be meaningful differences in students' achievement between the experimental group using WBI and the controlled group in a traditional instructive class. And the statistical calculations showed that the experimental group produced larger numbers in terms of both the average and standard deviation. Hypothesis 2 was that there would be the more highly rated outcomes from the experimental group applying WBI for students' interest, understanding, and concentration. The responses to a Questionnaire concerning stated items showed significant differences in favor of WBI class. Based on these analyses, this thesis represents an effort to potential application of WEI to learning of Poems, in light of research evidence that reveals its respective effect to further students' achievement and interest.

• Journal of Preventive Medicine and Public Health
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• v.42 no.5
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• pp.323-330
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• 2009

Objectives : The aim of this study was to investigate whether working married women in different occupational classes affected diverse health outcomes. Methods : We used data for married women aged 25-59 (N=2,273) from the 2005 National Health and Nutritional Examination Survey. Outcome measures included physical/mental and subjective/objective indicators (selfrated poor health, chronic diseases, depression, and suicidal ideation from reported results; metabolic syndrome dyslipidemia from health examination results). Agestandardized prevalence and logistic regression were employed to assess health status according to three types working groups (housewives, married women in manual jobs, married women in non-manual jobs). Sociodemographic factors (age, numbers of children under 7, education, household income) and health behaviors (health examination, sleep, rest, exercise, smoking, drinking) and a psychological factor (stress) were considered as covariates. Results : Non-manual married female workers in Korea showed better health status in all five health outcomes than housewives. The positive health effect for the non-manual group persisted in absolute (age-adjusted prevalence) and relative (odds ratio) measures, but multivariate analyses showed an insignificant association of the non-manual group with dyslipidemia. Manual female workers showed significantly higher age-adjusted prevalence of almost all health outcomes than housewives except chronic disease, but the associations disappeared after further adjustment for covariates regarding sleep, rest, and stress. Conclusions : Our results suggest that examining the health impact of work on married women requires the consideration of occupational class.

• Journal of the Korea Society for Simulation
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• v.21 no.2
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• pp.79-90
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• 2012

In this paper, a feature signal extraction method is proposed in order to enhance the low performance of fault detection caused by unbalanced data which denotes the situations when severe disparity exists between the numbers of class instances. Most of the cyclic signals gathered during the process are recognized as normal, while only a few signals are regarded as fault; the majorities of cyclic signals data are unbalanced data. SOM(Self-Organizing Map)-based feature signal extraction method is considered to fix the adverse effects caused by unbalanced data. The weight neurons, mapped to the every node of SOM grid, are extracted as the feature signals of both class data which are used as a reference data set for fault detection. kNN(k-Nearest Neighbor) and SVM(Support Vector Machine) are considered to make fault detection models with comparisons to Hotelling's $T^2$ Control Chart, the most widely used method for fault detection. Experiments are conducted by using simulated process signals which resembles the frequent cyclic signals in semiconductor manufacturing.

• Journal of Ocean Engineering and Technology
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• v.29 no.5
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• pp.366-372
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• 2015

Ocean energy is one of the most promising renewable energy resources. In particular, South Korea is one of the countries where it is economically and technically feasible to develop tidal current power plants to use tidal current energy. In this study, based on the design code for HARP_Opt (Horizontal axis rotor performance optimizer) developed by NREL (National Renewable Energy Laboratory) in the United States, and applying the BEMT (Blade element momentum theory) and GA (Genetic algorithm), the optimal shape design and performance evaluation of the horizontal axis rotor for a 200-kW-class tidal current turbine were performed using different numbers of blades (two or three) and a pitch control method (variable pitch or fixed pitch). As a result, the VSFP (Variable Speed Fixed Pitch) turbine with three blades showed the best performance. However, the performances of four different cases did not show significant differences. Hence, it is necessary when selecting the final design to consider the structural integrity related to the fatigue, along with the economic feasibility of manufacturing the blades.

• Journal of The Korean Association For Science Education
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• v.19 no.4
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• pp.560-569
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• 1999

This study was conducted with two science classes of the 8th grade students in Seoul during 4 weeks. The numbers of students in the classes were 37 and 38, and they were taught for 12 class hours. Questions obtained for 12 class hours from 75 students were analyzed and grouped into patterns. All together 1.108 questions from the students were classified into six categories: 'No Connection' (7%). 'Contradiction' (3%), 'Recall' (23%), 'Reframe' (40%), 'Application' (18%), and 'Extension' (9%). Irrelevant questions to learning and questions of false proposition were classified into 'No Connection' and 'Contradiction', respectively. Questions repeating what were already explained were grouped into 'Recall'. Those requiring other examples and/or additional explanations were grouped into 'Reframe'. Those requiring practical applications and/or explanations for other concrete facts were grouped into 'Application'. Finally. Questions for higher and/or other concepts were grouped into 'Extension'. We also discussed educational implications of the above categorized questions in this study.

• IMMUNE NETWORK
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• v.7 no.2
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• pp.80-86
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• 2007

Background: CD40-activated B (CD40-B) cells might be an attractive source of autologous antigen-presenting cells (APCs) for immunotherapy due to the convenience to obtain from peripheral blood and expand in vitro. Moreover, CD40-B cells were found to be comparable with DCs in their capacity to raise antigen-specific CD8+ T cells. Here, we have established K562 cells expressing CD40L to expand CD40-activated B cells used for APCs. Methods: After activation of B cell by K562/CD40L, CD40-B cells were examined by counting B cell numbers. Surface expression of CD54, CD80, CD86 and HLA class II was measured by flow cytometry. The CD40-B cells were tested for its function as APC by mixed lymphocyte reactions (MLR) and by induction of T cell responses specific for pp65 peptide in vitro. Results: The expansion of B cells by K562/CD40L increased about 6-folds compared with anti-CD40 or K562. Furthermore, the expression of CD54, CD80, CD86 and HLA class II was up-regulated by K562/CD40L. B cells by K562/CD40L showed comparable antigen presentation activity with mature DCs as shown in MLR, INF-${\gamma}$ ELISPOT assay. Conclusion: These results suggest that K562/CD40L could be used to generate activated B cells as potent APCs which could be useful for cellular vaccination and adoptive immunotherapy.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.465-465
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• 2009

Wind power is one of the most reliable renewable energy sources and the installed wind turbine capacities are increasing radically every year. Although wind power has been favored by the public in general, the problem with the impact of wind turbine noise on people living in the vicinity of the turbines has been increased. Low noise wind turbine design is becoming more important as noise is spreading more adverse effect of wind turbine to public. This paper demonstrates the design of 10 kW class wind turbines, each of three blades, a rotor diameter 6.4m, a rated rotating speed 200 rpm and a rated wind speed 10 m/s. The optimized airfoil is dedicated for the 75% spanwise position because the dominant source of a wind turbine blade has been known as trailing edge noise from the outer 25% of the blade. Numerical computations are performed for incompressible flow and for Mach number at 0.145 and for Reynolds numbers at $1.02{\times}10^6$ with a lift performance, which is resistant to surface contamination and turbulence intensity. The objective in the low design process is to reduce noise emission, while sustaining high aerodynamic efficiency. Dominant broadband noise sources are predicted by semi-empirical formulas composed of the groundwork by Brooks et al. and Lowson associated with typical wind turbine operation conditions. During the airfoil redesign process, the aerodynamic performance is analyzed to minimize the wind turbine power loss. The results obtained from the design process show that the design method is capable of designing airfoils with reduced noise using a commercial 10 kW class wind turbine blade airfoil as a basis. The new optimized airfoil clearly indicates reduction of total SPL about 3 dB and higher aerodynamic performance.