• Journal of The Korean Association For Science Education
• /
• v.31 no.6
• /
• pp.887-900
• /
• 2011

Teachers use explanations to communicate important scientific ideas to students. Consequently, all biology teachers should be evaluated to determine how effective they are at constructing and communicating biological explanations. Open response questions are required to detect pre-service biology teachers' abilities to communicate robust and accurate scientific explanations. Nevertheless, multiple-choice questions are typically preferred by educators because of the common drawbacks of using open-response instruments, such as scoring time, inter-rater scoring disagreements, and delayed feedback to test takers. This study aims to measure pre-service biology teachers' competence in building scientific explanations and to investigate how accurately multiple-choice questions predict the results of open-response questions. One hundred twenty four pre-service biology teachers participated in the study and were administered 20 multiple-choice items and three open-response items designed to measure the accuracy and quality of their explanations of evolutionary change. The results demonstrated that pre-service teachers displayed higher competence when tested with multiple choice items than when tested with open response items. Moreover, scores derived from multiple-choice items poorly predicted the scores derived from open-response items. Multiple-choice items were also found to be poor measures of the consistency, purity and abundance of conceptual elements in teachers' evolutionary explanations. Additionally, many teachers held mixed-models composed of both scientific and naive ideas, which were difficult to detect using multiple-choice formats. Overall, the study indicates that multiple-choice formats are poorly suited to measuring several aspects of biology teachers' knowledge of evolution, including their ability to generate scientific explanations. This study suggests that open-response items should be used in teacher education programs to assess pre-service teachers' explanatory competency prior to being permitted to teach science to children.

• Culinary science and hospitality research
• /
• v.19 no.3
• /
• pp.73-86
• /
• 2013

This study produced hot-air-dried perilla leaf to add Korea's popular perilla leaf to fresh noodles to examine their value as food and get the best fresh noodle recipe by adding 0%, 3%. 6%, 9%, and 12% of perilla leaf to flour. The moisture content of the dough was highest at 34.41% for the control group with 0% perilla leaf, whereas the pH was lowest at 5.59 for the dough with 12% perilla leaf. As a result of WRC analysis of the dough, moisture absorption increased with greater perilla leaf content. The moisture content of fresh noodles was lowest for the control group with 0% perilla leaf, whereas the pH was highest for the control group. The L, a, and b values of the dough were highest for the group with 0% perilla leaf powder. Hardness and cohesiveness were lowest for the 0% group and springiness tended to decrease with increased amounts of hot air-dried perilla leaf. The number of microorganisms decreased significantly with greater perilla leaf content on the third and fourth days. As a result of the sensory test, the 6% dough showed the highest scores for all items including appearance, flavor, color, taste, and texture. Overall acceptability was also highest at 7.20 for the 6% dough and lowest at 3.27 for the 12% dough. Based on the above results, when producing fresh noodles by adding hot-air-dried perilla leaf powder, inhibition of microorganisms improved with greater perilla leaf content for longer storage, but the sensory properties were best when 6% perilla leaf content was added.

• Journal of the Korea Concrete Institute
• /
• v.20 no.4
• /
• pp.439-449
• /
• 2008

Mineral admixtures are used to improve the quality of concrete and to develop sustainability of concrete structures. Supplementary cementitious materials (SCM), such as silica fume (SF), granulated blast furnace slag (GGBS) and pulverized fly ash (PFA), are gradually recognized as useful mineral admixture for producing high performance concrete. The study on ternary blended concrete utilizing mainly three major mineral admixtures is limited and the study on durability and chloride induced corrosion resistance of ternary blended concrete is very few. This study examines the durability characteristics of the ternary blended concrete composed of different amount of the SCM with ordinary Portland concrete and the study experimentally focuses on corrosion resistance evaluation of ternary blended concrete subjected to chloride attack. In this study, 50% replacement ratio of mineral admixture to OPC was used, while series of combination of $20{\sim}40%$ GGBS, $5{\sim}15%$ SF and $10{\sim}45%$ PFA binder were used for chloride corrosion resistance test. This study concerned the durability properties of the ternary blended concrete including the corrosion resistance, chloride binding, chloride transport and acid neutralization capacity. It was found that the ternary blended concrete utilizing the SCM densified the pore structures to lower the rate of chloride transport. Also, increased chloride binding and buffering to acid were observed for the ternary blended concrete with chlorides in cast.

• Journal of the Korea Concrete Institute
• /
• v.29 no.1
• /
• pp.43-51
• /
• 2017

As per current seismic design codes, diagonally reinforced coupling beams are restricted to coupling beams having aspect ratio below 4. However, a grouped diagonally reinforcement detail makes distribution of steel bars in the beam much harder, furthermore it may result in poor construction quality. This paper describes the experimental results of concrete coupling beam reinforced with high-strength steel bars (SD500 & SD600 grades). In order to improve workability for fabricating coupling beams, a headed large diameter steel bar was used in this study. Two full-scale coupling beams were fabricated and tested with variables of reinforcement details and aspect ratio. To reflect real behavior characteristic of the beam coupling shear walls, a rigid steel frame system with linked joints was set on the reaction floor. As a test result, it was noted that cracking and yielding of reinforcement were initially progressed at the coupling beam-to-shear wall joint, and were progressed to the mid-span of the coupling beam, based on the steel strain and failure modes. It was found that the coupling beams have sufficient deformation capacity for drift ratio of shear wall corresponding to the design displacement in FEMA 450-1. In this study, the headed horizontal steel bar was also efficient for coupling beams to exhibit shear performance required by seismic design codes. For detailed design for coupling beam reinforced with high-strength steel, however, research about the effect of variable aspect ratios on the structural behavior of coupling beam is suggested.

• Journal of Korean Society of Forest Science
• /
• v.89 no.3
• /
• pp.405-413
• /
• 2000

This study was conducted to develop an on-line monitoring system for a forest hydrological environment and its meteorological condition, such as temperature, wind direction and speed, rainfall and water level on V-notch, electrical conductivity(EC), potential of hydrogen(PH) by the motor drive sensor unit and measurement with a single-chip microprocessor as controller. These results are summarized as follows ; 1. The monitoring system consists of a signal process unit, motor drive sensor unit, radio modem unit and power supply. 2. The motor drive sensor unit protects the sensor from swift current or freezing and can constantly maintain fixed water level during measurements. 3. This monitoring system can transfer the data by radio modem. Additionally, this system can monitor hydrological conditions in real time. 4. The hardware was made of several modules with an independent CPU. They can be mounted, removed, repaired and added to. Their function can be changed and expanded. 5. These are the result of an accuracy test, the values of temperature, EC and pH measured within an error range of ${\pm}0.2^{\circ}C$, ${\pm}1{\mu}S$ and ${\pm}0.1pH$ respectively. 6. This monitoring system proved to be able to measure various factors for a forest hydrological environment in various experimental stations.

• Tuberculosis and Respiratory Diseases
• /
• v.83 no.3
• /
• pp.228-233
• /
• 2020

Background: The Bronchiectasis Health Questionnaire (BHQ) is a simple and repeatable, self-reporting health status questionnaire for bronchiectasis. We have translated the original version of the BHQ into Korean using a standardized methodology. The purpose of this study was to assess the validity of the Korean version of the BHQ (K-BHQ) with Korean patients. Methods: Stable state patients with bronchiectasis from two academic hospitals were enrolled in this study. The validity was assessed by investigating the relationship between the K-BHQ scores and the Korean version of the Chronic Obstructive Pulmonary Disease Assessment Test (K-CAT) scores. We also investigated the relationship between the K-BHQ scores and other variables of the modified Medical Research Council's (mMRC) dyspnea scale, lung function, and exacerbations. Results: A total of 126 patients with bronchiectasis were enrolled. The mean age was 64.3 (standard deviation [SD], 9.7). Women comprised 53.2% of the patients. The mean forced expiratory volume in one second (FEV₁) was 60% of the predicted value (SD, 18.9%); the mean K-CAT score was 17.6 (SD, 9.1). The K-BHQ scores correlated strongly with the K-CAT scores (r=-0.656, p<0.001). There was significant correlation between the K-BHQ scores and the mMRC dyspnea scale (ρ=-0.409, p<0.001), FEV₁ (r=0.406, p<0.001), and number of exacerbations requiring hospitalization (ρ=-0.303, p=0.001). Conclusion: The K-BHQ is valid for assessing the health-related quality of life or health status of Korean bronchiectasis patients.

• Journal of Families and Better Life
• /
• v.21 no.2
• /
• pp.1-18
• /
• 2003

In recent years, Korean society has witnessed an increased interest in the observance of everyday life proprieties, building healthy families, and psychological well-being of family members. The main purpose of this research was to examine the relationships among the practice of everyday life proprieties, dynamics of family systems, and psychological well-being of Korean married couples. A self-report Questionnaire was used to collect data from married couples with a child over four-years-old who are currently residing in Seoul. 513 couples(1026 individuals) were used for the final data analysis. Statistical analyses were conducted using frequencies, percentages, means, standard deviations, Cronbach'α, Pearson correlation, paired t-test, factor analysis, and multiple regression. The findings of this study are as follows: First, the level of the practice of everyday life propriety was relatively high in both husbands and wives, and no significant gender difference was found in the level. Yet, there were some statistically significant differences in certain sub-dimensions. Wives showed a higher degree of performance in public decorum and social etiquette, whereas husbands exhibited a higher degree of performance in family decorum and communication manners. The family systems were highly dynamic, according to both husbands and wives, and there was no difference between husbands and wives. As for the sub-dimensions, the extent of communication was found to be higher among husbands than among wives. Psychological well-being was again relatively high for both husbands and wives, with husbands significantly higher than wives. Second, the findings indicate that the causal model did fit the data well, and that a myriad of background variables had direct and indirect impacts on psychological well-being, and these relationships were mediated by several variables in the sub-dimension of proprieties observance, family adaptability, and the degree of communication. The implication is that the practice of life propriety, an intervening variable, is crucial in improving psychological well-being of married couples. The findings of this research demonstrate that there are significant causal relationships among the practice of everyday life propriety, family systems dynamics, and psychological well-being. In addition, the observance of proprieties is shown to be a concept that can be used as an important predictor in the area of family resource management. Further research is needed to expand its focus on the practice of proprieties in the family resource management. More concrete and specialized family life education programs should be developed to help build healthy families. Lastly, the results indicate that proprieties education needs to be incorporated in family policies in order to promote the quality of family life.

• Korean Chemical Engineering Research
• /
• v.51 no.4
• /
• pp.443-454
• /
• 2013

Various metal ions (transition and base metals) incorporated MCM-41 catalysts can be synthesized using colloidal and soluble silica with non-sodium involved process. Transition metal ion-typically $V^{5+}$, $Co^{2+}$, and $Ni^{2+}$-incorporated MCM-41 catalysts were synthesized by isomorphous substitution of Si ions in the framework. Each incorporated metal ion created a single species in the silica framework, single-site solid catalyst, showing a substantial stability in reduction and catalytic activity. Radius of pore curvature effect was investigated with Co-MCM-41 by temperature programmed reduction (TPR). The size of metallic Co clusters, sub-nanometer, could be controlled by a proper reduction treatment of Co-MCM-41 having different pore size and the initial pH adjustment of the Co-MCM-41 synthesis solution. These small metallic clusters showed a high stability under a harsh reaction condition without serious migration, resulting from a direct anchoring of small metallic clusters to the partially or unreduced metal ions on the surface. After a complete reduction, partial occlusion of the metallic cluster surface by amorphous silica stabilized the particles against aggregations. As a probe reaction of particle size sensitivity, carbon single wall nanotubes (SWNT) were synthesized using Co-MCM-41. A metallic cluster stability test was performed by CO methanation using Co- and Ni-MCM-41. Methanol and methane partial oxidations were carried out with V-MCM-41, and the radius of pore curvature effect on the catalytic activity was investigated.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.5
• /
• pp.78-88
• /
• 2016

Recently BIM technology has been expanded for using in construction project. However its spread has been delayed than the initial expectations, due to the high-cost of BIM infrastructure development, the lack of regulations, the lack of process and so forth. In design phase, especially, collaboration based on BIM system has being a key factor for successful next generation building project. Through the analysis of current research trend about IT technologies, virtualization and BIM service, data exchange such as drawing, 3D model, object data, properties using cloud computing and virtual server system is defined as a most successful solution. In various industrial fields, cloud computing technology is utilized as a promising solution which can reduce time and cost of hardware infrastructure. Among the cloud computing technology, VDI is receiving a great deal of attention from it market as an essential part cloud computing. VDI enables to host multiple individual virtual machines by using hypervisor. It has an advantage to easy main device management. Therefore, this study implements a step-by-step user's DaaS by analyzing the desktop resource data of the workers from Pre-design phase to Schematic design, Design develop and Construction design phase. It also develops BIM environment based on test of BIM modeler and designers in architectural design firm. The goal of the study is to enable the cloud computing BIM server. It provides cost saving, high-performance quality of working environment and cooperation's convenience and high security when doing BIM work in small and medium sized architectural design firm.

• Journal of dental hygiene science
• /
• v.6 no.1
• /
• pp.35-39
• /
• 2006

objective: The purpose of this study was to investigate job satisfaction of dental hygienist who were employed at the private dental clinic in Ulsan, Korea methods: The date obtained from some dental hygienists during 1 month. the survey was performed by face-by-face interview questionnaire consisting of 23 items and 6 point Likert type response format. The respondents were 77 from dental hygienists. The adjusted response rate was 88.5%(77/87). Data were analyzed using frequency distribution, independent T-test, ANOVA, chi-square and correlation. all statistical analyzed were conducted using Statistical Package for SPSS 11.5 result: In each factorial duty contentment, the level of the self-conceit from their own job was the highest. on contrary, the level of their monthly earnings was the lowest. In such a case as there was experience to move to another dental hospital, the job satisfaction was higher than nothing to move. conclusion: The dental hygienist who is in charge of protecting and hygiene of the teeth and the disease of oral has much influence of oral health. job satisfaction the dental hygienists have for their own job can influence themselves and even patients. So, making the job satisfaction higher is necessary to improve the quality of general dental hygiene.