• Journal of The Korean Association For Science Education
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• v.38 no.4
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• pp.451-465
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• 2018

The purpose of this study is to investigate the challenges of pre-service teachers for good science teaching with focus on the process of imparting meaning of teaching subject. We have detailed research questions such as, 'What the pre-service teachers thought about teaching subject? How they grasped the meaning of the teaching subject? and What kinds of methods they have used to expose the meaning in their classes?'. We had four pre-service teachers who took the class 'Teaching methods in physics teaching' as voluntary participants in the first semester of 2017. The results show that there are common features in the process of imparting meaning of the teaching subject. The participants started to think about fundamental/existential answer to the question, 'Why should we teach science to students?'. In addition, they grasped the meaning of the teaching subject by using the specific key words. And they tried to link the teaching components with the teaching subject as the center. This challenging process led pre-service teachers to form teachers' identity and to enhance teacher professionalism.

• Journal of Trauma and Injury
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• v.23 no.2
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• pp.75-82
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• 2010

Purpose: In Korea, trauma is the $3^{rd}$ most common cause of death. The trauma treatment system is divided into pre-hospital and hospital stages. Deaths occurring in the pre-hospital stage are 50% of the total death, and 20% of those are deaths that are preventable. Therefore, the purpose of our study is to calculate the preventable death rates caused by trauma in our current pre-hospital system, to analyze the appropriateness of the treatment of traumatized patients and to draw a conclusions about the problems we have. Methods: The study was done on traumatized patients who expired at the emergency department from January 1, 2005, to December 31, 2009, at the Korea University Medical Centers in Anam, Guro and Ansan. The data on the patients were reviewed retrospectively based on characteristics, conditions on admission and trauma severity. The patient's RTS (revised trauma score) and ISS (injury severity score) was calculated. Preventable death rate was calculated by TRISS (the trauma score-injury severity score). Results: A total of 168 patients were enrolled. All patients were intubated and underwent CPR. Of the total, 72% patients were male, and traffic accidents were the most common form of trauma (52.4%), falls being second (28.6%). Head injury, solitary or multiple, was the most common cause of death (55.4%). Thirty-eight (38, 22.6%) deaths were preventable. The 22.6% preventable death rate consisted of 15.5% potentially preventable and 7.1% definitely preventable deaths. Based on a logistic regression analysis, the relationship between the time intervals until transfusion and imaging and death was statistically significant in the hospital stage. In the pre-hospital stage, transit time from the site of the injury to the hospital showed a significant relationship with the mortality rate. Conclusion: One hundred sixty-eight (168) patients died of trauma at the 3 hospitals of Korea University Medical Center. The TRISS method was used to calculate the preventable death rate, with a result of 22.6%. The only factor that was significant related to the preventable death rate in the pre-hospital stage was the time from injury to hospital arrival, and the time intervals until transfusion and imaging were the two factors that showed significance in the hospital stage. Shortening the time of treatment in the field and transferring the patient to the hospital as quickly as possible is the most important life-saving step in the pre-hospital stage. In the hospital stage, the primary survey, resuscitation and diagnosis should proceed simultaneously.

• Journal of Korean Home Economics Education Association
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• v.31 no.1
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• pp.39-58
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• 2019

The purpose of this study was to investigate the home economics pre-service teachers' verbal interactions during their teaching practicum. For this purpose, the class interactions of four pre-service teachers were recorded, and the data were analyzed using advanced Flanders' verbal interaction analysis. The major findings are as follows: First, the item with the highest proportion of occurrences consisted of the pre-service teachers' 'lectures', 'nonverbal conditions' and 'asks questions'. 'forms a positive learning atmosphere' and 'praises or encourages' exhibited fewer occurrences, and there was little 'giving direction', 'criticizing students or justifying authority'. Second, the instances of class interactions appeared in the form of 'asks questions-student talk response' or 'lecture-asks questions', and in the last class were 'ask questions-student talk initiation' and 'accepts or uses ideas of students'. Third, trends of verbal interactions tend to be generally indirect, and students' remarks have appeared acceptable and compassionate. Fourth, according to expert analysis, 'class management questions' and 'diffusion questions' have increased. Pre-service teachers can guide students through their learning activities, and students can expand their thinking through the teachers' questions. As these results demonstrate, self-study analyses of pre-service teachers and active support in field are needed.

• Journal of The Korean Association For Science Education
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• v.42 no.1
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• pp.97-109
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• 2022

In this study, we investigated pre-service teachers' reflection of questions during science instruction in teaching practicum from the perspective of productive reflection. The productive reflection used in this analysis has four aspects of learners and learning, subject matter knowledge, instruction, and assessment. Five pre-service teachers participated in this study. They reflected on their questions with one class video by using think-aloud method. Semi-constructed interviews were also conducted. The analyses of the results reveal that the aspect of 'instruction' and the 'learners and learning' were frequently included in their reflections. 'subject matter knowledge' was often included in their reflection while 'assessment' was hardly included. The integrations of the two aspects appear most often, those of three aspects appear only sometimes. However, four aspects appear very rarely. The integrations of 'learners and learning' and 'instruction' with the other aspects were most frequent, and the integrations of 'content knowledge' with the other aspects were often. However, the integration of 'assessment' was very few. There were more productive reflections from pre-service teachers who reflect on several questions in context than who reflected on questions one by one. In addition, they exhibited some difficulties in suggesting alternatives to improve their questions. They tried to modify the teaching method related to the questions rather than revise the form of questions. Based on the results, practical implications to improve expertise related to the questions of pre-service teachers were discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.143-150
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• 1991

The data on reproductive performance of 1065 purebred Landrace, 1254 purebred Yorkshire. 553 purebred Duroc and 327 purebred Pietrain sows bred to farrow purebred litters and data from 3413 Landrace $\times$ Yorkshire, 487 Duroc $\times$ Pietrain and 3191 commericial litters were udsed in this study. The data were collected form litters farrowed form January 1986 to December 1988 in Holiday Hills Stock and Breeding Farms, San Prero, Laguna. The crossbred sows and litters were better in most traits associated with sow productivity than their contemporary purebred sows and litters. The Duroc $\times$ Pietrain crossbred litters showed 16.67% improvement in litter size at weaning, 10.11% improvement in survival rate form birth to weaning and 16.21% more pigs per sow pre year than the averages of their parental breeds. The litters from the Landrace $\times$ Yorkshire crossbred sows sired by either Duroc or Duroc $\times$ Pietrain boars had 11.01% bigger litter size at birth, 20.74% increase in litter size at weaning and 22.86% more pigs weaned per sow per year than the averages of the four parental breeds. Very little improvement in most traits evaluated were observed form the Landrace $\times$ Yorkshire crossbred litters compared with their parental breeds. Year of birth of litter had litter influence on sow productivity. However, the reproductivity performance declined when sows farrowed in June up to September. The best Months of farrowing were found to be from January to April. The breed $\times$ year, breed $\times$ month and year $\times$ month had no significant effects on all traits evaluated.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.7
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• pp.171-178
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• 2019

Auto Climbing Formwork System (ACS) for construction of high-rise building is a construction method for automatically lifting the formwork system supported by the anchor on the pre-constructed concrete wall. It has excellent construction speed and quality, but it has the possibility of structural failure depending on the quality of concrete and also has low economical efficiency due to the use of foreign technology. In order to overcome these problems, this study conducted an optimum design for the development of a new concept of Corner Supported Auto Climbing System (CS-ACS) in conjunction with the development of corner steel-reinforced concrete core wall system. For the design the formwork system, the basic module and structural member compositions were planned, and the structural analysis program was used to analyze the optimum member's cross section and spacing. As a result, the horizontal displacement and the stress of the horizontal members were influenced by the spacing more than the cross-section of the member. On the other hand, vertical members did not affect the displacement and stress of the formwork system. The form tie was very effective in controlling the displacement when adjusting the spacing of the horizontal members, but when the spacing of the form tie is more than 1,500mm, it is analyzed that form tie is yielding in basic module. When the span of the formwork system is more than 30m, it is analyzed that the basic module needs to be changed because of the increase of overall displacement.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1139-1146
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• 2002

Sixty crossbred Anglo-Nubian goats (growing females), 18-24 mo of age, with a mean pre-experimental live weight of $20.9{\pm}0.44kg$ were used to investigate voluntary dry matter intake (DMI) and digestibility of supplements of Leucaena leucocephala (LL) leaves to a basal diet of guinea grass. The experiment was a 3 forms of presentation: fresh, wilted and $dry{\times}4$ levels of supplementation: 10, 20, 30 and 40% of total forage allowance with LL leaves. The goats were assigned based on weight and age to one of the twelve diets in a randomized manner and each level had five animals (replicates) per diet for 56 days. The form of presentation of LL leaves had effects on dry matter (DM) and nutrient composition. DM and NDF were higher in the dry LL leaves (p<0.05). In the diets, CP increased as the level of supplementation with LL leaves increased (p<0.05). Mean CP was similar in the fresh ($14.8{\pm}3.5%$), wilted ($14.3{\pm}3.3%$) and dry forms ($13.9{\pm}3.1%$). Neutral detergent fibre (NDF) decreased linearly (p<0.05) with increase in levels of supplementation. Organic matter (OM) followed the trend of CP concentration (p<0.05). Drying was observed to reduce the availability of CP at the different levels of supplementation and subsequently this affected the NDF of the diets. DM intake of the goats on the fresh and wilted LL leaves was significantly higher (p<0.05) than in those on the dry LL leaves. DM intake of the basal diet was observed to decrease as the level of supplementation (p<0.05) increased regardless of the form of presentation of LL. Growth rate was best (p<0.05) on the fresh form followed by wilted and the least in the dry form. Growth rate decreased linearly (p<0.05) with increase in the level of supplementation in the dry form. The form of presentation and level of supplementation influenced DM, CP and OM digestibility (p<0.05). Except for NDF, the digestibility of DM, CP and OM were better (p<0.05) in the goats on fresh LL leaves compared to the wilted and dry leaves. Based on the data on DMI, growth rate and apparent nutrient digestibility coefficients, the results suggest that LL leaves is best utilized when fed fresh or wilted to goats. In the dry form of presentation, the best level of supplementation without a reduction in voluntary DMI and growth rate is the 20%. In the fresh and wilted form, LL leaves could be fed up to the 40% level with improved DMI, growth rate and nutrient utilization.

• Journal of Ship and Ocean Technology
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• v.3 no.2
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• pp.27-48
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• 1999

The paper is concerned with application to develop the expert system, which structural analysis and design process for tower cranes. The system is organized into three groups. One is pre-processor for creating input data files, another is `model former' which combines knowledge-base with inference engine for automatic generating structural analysis models, a third is application group for final analysis checks. In this study, geometric subroutine of `model former' designates node positions, nodes, elements numbers and element types. Load data subroutine computes weight of tower crane and device, slewing force, cargo load, wind force form rules or equations in knowledge-base. Also, Property and boundary subroutine applies element properties and boundary conditions to suitable elements and nodes. Design and analysis expert system for tower crane integrates these subroutine, `model former' and pre-processor. RBR(Rule-Base Reasoning) was adopted for a reasoning strategy of this expert system. And this expert system can produce structural analysis model and data, which can be used in ordinary structural analysis program (SAP, ADINA or NASTRAN, etc.). In this paper, this expert system produces format of the analysis model data, which are used in MSC/NASTRAN. The main discussions included in the paper are introduction of the tower crane and structural analysis, composition of the design expert system for tower crane and structural analysis using the expert system.

• Transactions of Materials Processing
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• v.4 no.2
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• pp.169-179
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• 1995

Static restoration mechanism during hot interrupted deformation of Cu-Zn alloy was studied in the temperature range from $550^{\circ}C$ to $750^{\circ}C$ and at a constant strain rate of 0.1/sec. At a given temperature, the hot interrupted deformations were performed with variation of interrupted time $t_i$ form 1 to 50 sec and of interrupted strain ${\varepsilon}_i$ from 0.15 to 0.90. From the analysis of the values of the critical strain of ${\varepsilon}_c$ for tje initiation of dynamic recrystallization and the peak strain of${\varepsilon}_p$, the relationship ${\varepsilon}_c{\fallingdotseq}0.7{\varepsilon}_p$ was obtained. It was clarified that the softening of the interrupted deformation was mainly the static recrystallization and the fractional softening(FS) which was over 30% mostly confirmed this result. The fractional softening of the interrupted time $t_i$ especially and pre-strain. The FS increased with increasing strain rate, interrupted time and pre-strain. The change of microstructures after hot deformation could be predicted by the FS. when the FS was 30~100%, static recrystallization was happened and grain growth was observed at the condition which was $750^{\circ}C$ deformation temperature, 0.45 prestrain and this condition's FS value was over 100%.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.90-97
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• 2017

Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.