• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.157-172
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• 2023

Controlled pollination (CP) is an important method in tree breeding programs because CP quickly generates desirable genotypes and rapidly maximizes genetic gains. However, few studies have evaluated the efficiency and success rate of CP in the breeding program of Pinus densiflora. To evaluate CP and the management of control pollinated progenies, we used 159 individuals in CB2 × KW40 or KW40 × CB2 populations that were established in 2015. After genotyping microsatellite loci, we estimated whether the number of primers was sufficient or not. Then, we performed pedigree analysis. The result showed that the number of primers was sufficient. By pedigree analysis, we found out that 60 of 159 individuals had been generated by the mating between CB2 and KW40. In the maternity analysis, there was evidence to indicate the possibility of management problems. Therefore, we excluded 54 individuals and repeated the pedigree analysis. In the second analysis, 47 of 105 individuals were generated by the mating between CB2 and KW40. To increase the efficiency of CP in tree breeding programs, several precautions are required. It is necessary to identify the exact clone names of the mother and father trees. In addition, CP processes should be performed properly, including deciding on the schedule of CP and the isolation of female strobili or flowers. Finally, the monitoring of hybrid progenies management after mating is important. Molecular markers should be used to identify the clone names of the mother and father trees and for monitoring post hoc management. This study provides a reference for tree breeding programs for the future control pollination of pine species.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.1
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• pp.18-25
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• 2022

Purpose: This study aimed to evaluate the color stability and antibacterial properties of the surface of polyethyl methacrylate (PEMA) resin with zirconia nanoparticles added. Materials and Methods: The control group was pure PEMA resin, and the experiment group was PEMA resin 15 mm in diameter and 2.5 mm in thickness disk-shaped specimens with 2, 4 and 8 w/v% of zirconia nanoparticles added, which were respectively divided into Group Z2, Group Z4, and Group Z8. After analyzing the surface roughness and color stability of the specimens, their antibacterial properties were evaluated using Porphyromonas gingivalis (P. gingivalis). The Statistical analysis was performed using when normality was met in the Shapiro-Wilk test, one-way ANOVA was used to test parameters, and Tukey's test was used as a post hoc test. When normality was not met, the Kruskal-Wallis test, a non-parametric test was used (P < 0.05). Results: The surface roughness measurement found that there was no significant difference between the experimental and control groups. The color stability evaluation showed that the Z2, Z4, and Z8 groups were within the color range of natural teeth. The adhesion of P. gingivalis was evaluated to be significantly reduced in Group Z2 compared to the control group (P < 0.05). In the Z2 group, Z4 group, and Z8 group, dead cells bacteria than the control group were observed. Conclusion: In conclusion, PEMA resin with zirconia nanoparticles added was within the range of natural teeth in color and reduced the adhesion of P. gingivalis.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.1-11
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• 2016

With increasing interest, there have been studies on LiDAR(Light Detection And Ranging)-based DEM(Digital Elevation Model) to acquire three dimensional topographic information. For producing LiDAR DEM with better accuracy, Filtering process is crucial, where only surface reflected LiDAR points are left to construct DEM while non-surface reflected LiDAR points need to be removed from the raw LiDAR data. In particular, the changes of input values for filtering algorithm-constructing parameters are supposed to produce different products. Therefore, this study is aimed to contribute to better understanding the effects of the changes of the levels of GroundFilter Algrothm's Mean parameter(GFmn) embedded in FUSION software on the accuracy of the LiDAR DEM products, using LiDAR data collected for Hwacheon, Yangju, Gyeongsan and Jangheung watershed experimental area. The effect of GFmn level changes on the products' accuracy is estimated by measuring and comparing the residuals between the elevations at the same locations of a field and different GFmn level-produced LiDAR DEM sample points. In order to test whether there are any differences among the five GFmn levels; 1, 3, 5, 7 and 9, One-way ANOVA is conducted. In result of One-way ANOVA test, it is found that the change in GFmn level significantly affects the accuracy (F-value: 4.915, p<0.01). After finding significance of the GFmn level effect, Tukey HSD test is also conducted as a Post hoc test for grouping levels by the significant differences. In result, GFmn levels are divided into two subsets ('7, 5, 9, 3' vs. '1'). From the observation of the residuals of each individual level, it is possible to say that LiDAR DEM is generated most accurately when GFmn is given as 7. Through this study, the most desirable parameter value can be suggested to produce filtered LiDAR DEM data which can provide the most accurate elevation information.

• Strategy21
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• s.34
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• pp.236-261
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• 2014

The future role of nuclear extended deterrence in the security alliance between the United States and the Republic of Korea is currently a central concern. The gradually lessening role of reliance on nuclear weapons in US security policies broadly, combined with increasing North Korean nuclear capabilities and belligerence, raise fresh questions about the sufficiency of the "nuclear umbrella" as a pillar of the US-ROK defense posture. This article addresses the current and future role of nuclear extended deterrence in Korea in this dynamic context. The article reviews the longstanding trend toward reducing the overall size of the US nuclear arsenal, and assesses developments in US-ROK outlooks toward extended deterrence in response to the Obama administration's nuclear policies and North Korea's recent smaller-scale aggressions. The analysis finds that the challenges of deterrence credibility and allied reassurance are difficult and long-term. The analysis explains how these challenges emerge less from a shrinking US numerical arsenal size than from the sufficiency of specific nuclear and non-nuclear capabilities to meet emerging smaller-scale threats. The analysis also highlights the importance of broader strategic and political interaction in sustaining allied confidence in any joint security posture. The evaluation concludes that a strong US-ROK alliance relationship can be maintained while the size of the US nuclear arsenal continues to decline, in part because nuclear weapons in any deployment configuration are relatively ineffective means for deterring smaller-scale aggression. Nevertheless, continuing adjustment of the US-ROK extended deterrence posture to the evolving, complex and uncertain Korean peninsula security environment will remain an ongoing challenge. Finally, the article encourages further examination of the potential specific role ROK maritime forces might serve in enhancing deterrence of smaller-scale threats while minimizing risks of conflict escalation.

• Asia Marketing Journal
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• v.12 no.2
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• pp.1-25
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• 2010

Motion pictures are so typical experience goods that consumers tend to look for more credible information. Hence, movie audiences consider movie viewers' reviews more important than the information provided by the film distributor. Recently many portal sites allow consumers to post their reviews and opinions so that other people check the number of consumer reviews and scores before going to the theater. There are a few previous researches studying the electronic word of mouth(eWOM) effect in the movie industry. They found that the volume of eWOM influenced the revenue of the movie significantly but the valence of eWOM did not affect it much (Liu 2006). The goal of our research is also to investigate the eWOM effects in general. But our research is different from the previous studies in several aspects. First, we study the eWOM effect in Korean movie industry. In other words, we would like to check whether we can generalize the results of the previous research across countries. The similar econometric models are applied to Korean movie data that include 746,282 consumer reviews on 439 movies. Our results show that both the valence(RATING) and the volume(LNMSG) of the eWOM influence weekly movie revenues. This result is different from the previous research findings that the volume only influences the revenue. We conjectured that the difference of self construal between Asian and American culture may explain this difference (Kitayama 1991). Asians including Koreans have more interdependent self construal than American, so that they are easily affected by other people's thought and suggestion. Hence, the valence of the eWOM affects Koreans' choice of the movie. Second, we find the critical defect of the previous eWOM models and, hence, attempt to correct it. The previous eWOM model assumes that the volume of eWOM (LNMSG) is an independent variable affecting the movie revenue (LNREV). However, the revenue can influence the volume of the eWOM. We think that treating the volume of eWOM as an independent variable a priori is too restrictive. In order to remedy this problem, we employed a simultaneous equation in which the movie revenue and the volume of the eWOM can affect each other. That is, our eWOM model assumes that the revenue (LNREV) and the volume of eWOM (LNMSG) have endogenous relationship where they influence each other. The results from this simultaneous equation model showed that the movie revenue and the eWOM volume interact each other. The movie revenue influences the eWOM volume for the entire 8 weeks. The reverse effect is more complex. Both the volume and the valence of eWOM affect the revenue in the first week, but only the volume affect the revenue for the rest of the weeks. In the first week, consumers may be curious about the movie and look for various kinds of information they can trust, so that they use the both the quantity and quality of consumer reviews. But from the second week, the quality of the eWOM only affects the movie revenue, implying that the review ratings are more important than the number of reviews. Third, our results show that the ratings by professional critics (CRATING) had negative effect to the weekly movie revenue (LNREV). Professional critics often give low ratings to the blockbuster movies that do not have much cinematic quality. Experienced audiences who watch the movie for fun do not trust the professionals' ratings and, hence, tend to go for the low-rated movies by them. In summary, applied to the Korean movie ratings data and employing a simultaneous model, our results are different from the previous eWOM studies: 1) Koreans (or Asians) care about the others' evaluation quality more than quantity, 2) The volume of eWOM is not the cause but the result of the revenue, 3) Professional reviews can give the negative effect to the movie revenue.

• Journal of Animal Science and Technology
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• v.66 no.5
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• pp.962-980
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• 2024

Antimicrobial resistance poses challenges to humans and animals, especially to the poultry sector in control of fowl typhoid with antibiotics, leading to increased mortality and food insecurity. Therefore, it is essential to develop more effective medications as alternatives to antibiotics. Currently, zinc oxide and copper oxide nanoparticles are of such significant interest due to their antibacterial properties. This study aimed to evaluate antimicrobial activity of zinc oxide and copper oxide nanoparticles against fowl typhoid in broilers. Ninety broiler chicks were raised under suitable management conditions. On day 10 of age, chicks were divided into six groups: control negative, control positive, T₁, T₂, T₃, and T₄. On day 19 of age, chicks in all groups except control negative were infected with Salmonella gallinarum (0.2 mL, 10⁸ CFU/mL). After appearance of clinical signs, the treatments (Florfenicol; 50 mg/L drinking water [T₁], and zinc oxide + copper oxide nanoparticles; 25 + 10 mg/kg/d [T₂], 37.5 + 15 mg/kg/d [T₃], and 50 + 20 mg/kg/d [T₄]) were administered to chicks. Chicks were sacrificed on 26th and 30th day of age, and samples of blood and tissue were obtained. Hematological analysis with gross and histopathological examination of spleen, thymus and bursa of Fabricius was performed. Results revealed that there was no visible congestion in spleen and thymus of T₃ and T₄ at 11th day post infection. Antibody level against new castle's disease and lymphoproliferative response showed no significant difference in all groups. However, phagocytic response in nanoparticles treated groups exhibited a notable (p < 0.01) distinction compared to control positive. Notably, T₃ demonstrated the highest level of phagocytic activity. Hematological parameters, including lymphocytes, heterophils, eosinophils, and heterophils/lymphocytes ratio in groups T₂, T₃, and T₄, indicated significant (p < 0.01) difference compared to control positive. However, lymphocytes, heterophils, and heterophils/lymphocytes ratio in groups T₂, T₃, and T₄ showed no significant difference when compared to T₁. Nanoparticle treated groups showed decreased (p < 0.01) congestion of spleen and thymus as compared to control positive. Overall, zinc oxide and copper oxide nanoparticles have potential to serve as an alternative to florfenicol in treatment of fowl typhoid.

• Journal of the Korean Chemical Society
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• v.68 no.5
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• pp.259-273
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• 2024

This study aimed to investigate changes in metamodeling recognition among chemistry teachers through a teacher educational program related to redox models and water electrolysis experiments. To this end, a science model education program was developed for 9 chemistry teachers and conducted over 10 lessons for a total of 40 hours. In addition, a pre- and post-survey was administered to determine teachers' metamodeling recognition in non-contextual and contextual situations. As a result of the study, through the science model education program, teachers showed educational effects in both non-contextual and contextual situations. In the case of non-contextual situations, the stages of scientific metamodeling knowledge development of chemistry teachers came out differently depending on the type of question. For example, the nature or purpose of the model, the modeling process, or the evaluation and improvement of the model improved from low to high, but there was no significant change because the perception of model change and diversity was already high in advance. In the case of contextual situations, the stage of scientific metamodeling knowledge development improved from objectivity to subjectivity in both the redox model theory class and the water electrolysis model experiment class. Therefore, through the 5E circular learning model-based education program, chemistry teachers' perception of metamodeling was clearly improved. However, the modeling activities of teachers in the water electrolysis model experiment class were different from the change in metamodeling perception. The types that teachers selected as additional experiments for modeling were analyzed in two ways. The first type is when they are interested in finding an ideal condition in which the ratio of hydrogen and oxygen gas is close to 2:1 through additional experiments. The second type is when additional experiments are designed with interest in why the experimental results are coming out like that. It was analyzed that the second type was the experiment necessary for modeling. In addition, modeling activities were analyzed into two types. The first was a type in which water molecules were directly decomposed in two electrodes to generate hydrogen and oxygen gas. This type was the case of regression to the textbook model regardless of the experimental results, and 6 chemistry teachers out of 8 were analyzed as this type. The second type was the type in which water reacted at the (+) electrode to generate other substances, and hydrogen ions reacted at the (-) electrode to generate hydrogen gas. Teachers who performed these modeling activities corresponded to the second type in additional experiments, and 2 chemistry teachers out of 8 corresponded to this. Therefore, it is necessary to provide an experience of activities corresponding to the second type of experiment and modeling through an educational program that provides an experience of directly modeling through experiments in order to develop modeling capabilities, unlike the development of metamodeling knowledge.

• Journal of Korea Water Resources Association
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• v.57 no.8
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• pp.509-518
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• 2024

Flash drought is a rapid-onset drought that occurs rapidly over a short period due to abrupt changes in meteorological and environmental factors. In this study, we utilized satellite-based soil moisture product from the Advanced Microwave Scanning Radiometer-2(AMSR2) ascending X-band to calculate the weekly Flash Drought Intensity Index (FDII). We also analyzed the characteristics of flash droughts on the Korean Peninsula over a 10-year period from 2013 to 2022. The analysis of monthly spatial distribution patterns of the irrigation period across the Korean Peninsula revealed significant variations. In North Korea (NK), a substantial increase in the rate of intensification (FD_INT) was observed due to the rapid depletion of soil moisture, whereas South Korea (SK) experienced a significant increase in drought severity (DRO_SEV). Additionally, regional time series analysis revealed that both FD_INT and DRO_SEV were significantly high in the Gangwon province of both NK and SK. The estimation of probability density by region revealed a clear difference in FD_INT between NK and SK, with SK showing a higher probability of severe drought occurrence primarily due to the high values of DRO_SEV. As a result, it is inferred that the occurrence frequency and damage of flash droughts in NK are higher than those in SK, as indicated by the higher density of large FDII values in the NK region. We analyzed the correlation between DRO_SEV and the Evaporative Stress Index (ESI) across the Korean Peninsula and confirmed a positive correlation ranging from 0.4 to 0.6. It is concluded that analyzing overall drought conditions through the average drought severity holds high utility. These findings are expected to contribute to understanding the characteristics of flash droughts on the Korean Peninsula and formulating post-event response plans.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.12-21
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• 2024

The aim of this research was to investigate the effect of gibberellin on improving seedling growth characteristics and enhancing strawberry quality in cutting propagation. Cuttings of the cultivar 'Seolhyang' were treated with GA₃ for 30 and 60 minutes at concentrations of 50, 100, and 150 mg·L^-1, with distilled water used for dipping as the control. Evaluation of seedling growth showed a positive correlation between the duration of gibberellin dipping and growth characteristics such as leaf number and SPAD value. Plant height, petiole length, leaf length and width, and leaf area varied significantly based on the interaction between dipping time and concentration. Crown diameter exhibited differences depending on the dipping time, with cuttings producing superior seedlings having a diameter of 8.0 mm or more for all treatments except the 30-minute, 100 mg·L^-1 treatment. The T/R ratio was significantly lower in the 30-minute, 50 mg·L^-1 treatment, indicating the highest plant vigor. Quantum yield was lower at a concentration of 150 mg·L^-1, showing a decreasing trend with increasing gibberellin concentration. Nonphotochemical quenching was significantly smaller in the 30-minute, 150 mg·L^-1 treatment, indicating an effective reduction of stress in the cuttings. Antioxidant content was highest in the 30-minute, 50 mg·L^-1 treatment and the 60-minute, 150 mg·L^-1 treatment. Moreover, the results of post-transplanting growth assessment showed no negative effect of gibberellin on flowering induction. Therefore, it was confirmed that gibberellin treatment during the cutting propagation of 'Seolhyang' strawberries had a positive effect on the production of high-quality seedlings. Dipping the cuttings in 50 mg·L^-1 gibberellin for 30 minutes is considered to be the most suitable method for improving growth and quality compared to the control.

• The Korean Journal of Rehabilitation Nursing
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• v.2 no.2
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• pp.257-270
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• 1999

The purpose of this study is to investigate factors related to the intent of using home nursing of chronic disease patients who got out of a university hospital. For the purpose, the study selected 153 patients who were hospitalized and left K university hospital with diagnoses of cancer, hypertension, diabetes and cerebral vascular accident and ordered to be discharged and performed interviews with them and surveys on their medical records to obtain the following results. For this study a direct-interview survey and medical record review was conducted from June 28 to Aug. 30, 1998. The frequency and mean values were computed to find the characteristics of the study subjects, and $X^2$-test, t-test, factor analysis and multiple logistic regession analysis were applied for the analysis of the data. The following results were obtained. 1) When characteristics of the subjects were examined, men and women occupied for 58.8% and 41.2%, respectively. The subjects were 41.3 years old in aver age and had the monthly aver age earning of 0.99 million won or below, which was the most out of the total subjects at 34.6%. Among the total, 87.6% resided in cities and 12.4 in counties. The most left the hospital with diagnosis of cancer at 51.6%, followed by hyper tension at 24.2%, diabetes at 13.7% and cerebral vascular accident at 7.2%. 2) 93.5% of the selected patients had the intent of using home nursing and 6.5%, didn't. Among those patients having the intent, 85.6% had the intent of paying for home nursing and 14.4%, didn't. The subjects expected that the nursing would be paid 9,143 won in aver age and 47.7% of them preferred national authorities as the main servers. 86.3% of the subjects thought that home nursing business had the main advantage of making it possible to learn nursing methods at home and thereby contributing to improving the ability of patients and their facilities to solve health problems. 3) Relations between the intent of use and characteristics of the subjects such as demography-related social, home environment, disease and physical function characteristics did not show statistically significant differences among one another. Compared to those who had no intent of using home nursing, the group having the intent had more cases of male patients, the age of 39 or below, residence in cities, 5 family member s or more, no existence of home nursing servers, leaving the hospital from a non-hospitalized building, disease development for five months or below, hospitalization for ten days or more, non-hospitalization with in the recent one month, two times or over of hospitalization, leaving the hospital with no demand of special treatment, operation underwent, poor results of treatment, leaving the hospital with demand of rehabilitation services, physical disablement and high evaluation point of daily life. 4) Among those patients having the intent of using home nursing, 47.6% demanded technical nursing and 55.9%, supportive nursing. As technical nursing,' inject into a blood vessel ' and 'treat pustule and teach basic prevention methods occupied for 57.4%, respectively, topping the list. Among demands of supportive nursing, 'observe patients 'status and refer them to hospitals or community resources as available, if necessary' was the most with percent age point of 59.5. Regarding the intent of paying for home nursing, 39.2% of those patients wishing to use the nursing responded paying for technical services and 20.2, supportive services. In detail, 70.0% wanted to pay for a service stated as 'inject into a blood vessel', highest among the former services and 30.7%, a service referred to as 'teaching exercises needed to make the body of patients move', highest among the latter. When this was analyzed in terms of a relation between the need(the need for home nursing) and the demand(the intent of paying for home nursing), The rate of the need to the demand was found two or three times higher in technical nursing(0.82) than in supportive nursing(0.35). In aspects of tech ical nursing, muscle injection(1.26, the 1st rank) was highest in the rate while among aspects of supportive nursing, a service referred to as 'teach exercises needed for making patients move their bodies normally'(0.58, the 1st rank). 5) factors I(satisfaction with hospital services), II(recognition of disease state), III(economy) and IV(period of disease) occupied for 34.4, 13.8, 11.9 and 9.2 percents, respectively among factors related to the intent by the subjects of using home nursing, totaled 59.3%. In conclusion, most of chronic disease patients have the intent of using hospital-based home nursing and satisfaction with hospital services is a factor affecting the intent most. Thus a post-management system is needed to continue providing health management to those patients after they leave the hospital. Further, supportive services should be provided in order that those who are satisfied with hospital services return to their community and live their in dependent lives. Based on these results, the researcher would make the following recommendation. 1) Because home nursing becomes more and more needed due to a sharp increase in chronic disease patients and elderly people, related rules and regulations should be made and implemented. 2) Hospital nurses specializing in home nursing should be cultivated.