• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.5
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• pp.230-234
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• 2013

IR cut-off thin films consisted of ATO nanoparticles were successfully fabricated by sol-gel method. The coating solution was synthesized with organic/inorganic hybrid binder and ATO colloidal solution and ATO thin films were coated on a slide glass with the withdrawal speed of 5~40 mm/s. As the withdrawal speed increased from 5 mm/s to 40 mm/s, the thickness of coating thin films also increased from $1.05{\mu}m$ to $4.25{\mu}m$ and the IR cut-off in wavelength of 780~2500 nm increased from 49.5 % to 66.7 %. In addition, the pencil hardness of ATO thin films dried at $80^{\circ}C$ was ca. 5H and the coating films were not removed after a cross cutter tape test because of the hybrid binder synthesized with tetraethylorthosilicate and methyltrimethoxysilane. The surface morphologies, optical properties and film thickness of prepared thin films with a different withdrawal speed were measured by field emission scanning electron microscope (FE-SEM), UV-Vis spectrophotometer, and Dektak.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.49-54
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• 2020

To attach a stretchable/flexible electrode to something or something to on electrode, conductive adhesives must be stretchable/flexible to suit the properties of the electrode. In particular, conductive adhesive require durability and heat resistance, and unlike conventional adhesives, they should also have conductivity. To this end, Epoxy, which has good strength and adhesion, was selected as an adhesive, and a plasticizer and a reinforcement were mixed instead of a two-liquid material consisting of a conventional theme and a hardener, and a four-liquid material was used to give stretchability/flexibility to high molecules. The conductive filler was selected as silver, a material with low resistance, and for high conductivity, three shapes of Ag particles were used to increase packing density. Conductivity was compared with these developed conductive adhesives and two epoxy-based conductive adhesives being sold in practice, and about 10 times better conductivity results were obtained than products being actually sold. In addition, conductivity, mechanical properties, adhesion and strength were evaluated according to the presence of plasticizers and reinforcement agent. There was also no problem with 60% tensile after 5 minutes of curing at 120℃, and pencil hardness was excellently measured at 6H. As a result of checking the adhesion of electrodes through 3M tape test, all of them showed excellent results regardless of the mixing ratio of binders. After attaching the Cu sheet on top of the electrode through conductive adhesive, the contact resistance was checked and showed excellent performance with 0.3 Ω.

• Journal of Technologic Dentistry
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• v.29 no.1
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• pp.121-131
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• 2007

A preparation process's conditions of aqueous sol which contains anatase-type nano titania particles with photocatalyic properties was established by using Yoldas process, so called, DCS(Destabilization of Colloidal Solution) process in this study. And crystal size change and phase transformation of titania particles in aqueous titania sol depending on reaction conditions was investigated by a light scattering method and XRD analysis of frozen dried powders, respectively. This sol with photo catalytic nano titania particles was used to the following hydrophilic hybrid coating film's fabrication and its properties was evaluated. Subsequently, for coating film using the above mentioned aqueous titania sol, non-aqueous titania sol was prepared without any chemical additives and its time stability according to aging time was investigate. By using the above mentioned aqueous titania sol and non-aqueous sol, a complex oxide coating sol for metal and ceramic substrate and a organic-inorganic hybrid coating sol for polymer substrate was prepared and it's hydrophilicity depending on UV irradiation conditions was evaluated. As a conclusions, the following results were obtained. (1)Aqueous titania sol The average particle size of titania in formed aqueous titania sol was distributed between 20$\sim$90nm range depending on reaction conditions. And the crystal phase of titania powders obtained by frozen drying method was changed from amorphous state to anatase and subsequently transformed to rutile crystal phase and it is attributed to concentration gradient in aqueous sol. (2)Non-aqueous titania sol Non-aqueous titania sol was prepared using methanol as a solvent and a little distilled water for hydrolysis and nitric acid as a catalyst were used. The obtained non-aqueous titania sol was stable at room temperature for 20 days. Additionally, non-aqueous titania sol with addition of chealating reagent such as acethylaceton and ethylene glycol prolonged the stability of sol by six months. (3)Complex sol and hybrid sol with super hydrophilicity The above mentioned aqueous titania sol as a main photocataylic component and non-aqueous titania sol as a binder for coating process was used to prepare a complex sol used for metal, ceramic and wood material substrate and also to prepare the organic-inorganic hybrid sol for polymer substrate such as polycarbonate and polyethylene, in which process APMS(3-Aminopropyltrimethoxysilane), GPTS(3-Glycidoxypropyl-trimethoxysilane) as a hydrophilic silane compound and HEMA(2-Hydroxyethyl methacrylate) as a forming network in hybrid coating film were used. The hybrid coating film such as prepared through this process showed a superhydrophilicity below 1$10^{\circ}$ depending on processing conditions and a pencil's hardness over 6 H.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.1
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• pp.23-37
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• 1999

This study is to understand and to describe the power that a nurse experiences on nursing practice and then. to present a basic data for nurse's power-development, power improving and empowering. Ethnography was used to understand and to describe experience on exercising various powers occurred on nursing practice. and to analyze and to understand the meaning of a nurse's power. The objects was nurses. Ten nurses who have more than three year's experience were selected as objects from Cuniversity's hospital in Seoul from May of 1996 to August of 1997 through in-depth interview. participant observation, and phone interview. Instruments werw a portable recorder and field notes. I described a case appeared in a data using Agar's 'Pencil and scissors' method right after collecting materials. Then, Idescribed a theme discovered commonly. Followings are the results of the study. 1. There were three categories of relationships with main objects when nurses exercised their power on their practices: a therapeutic caring relationship with patients, a relationship of companion, vertical cooperation, and a constituent person with a doctor, and a relationship of cooperation, and a constituent person with administrative workers and medical technicians. 2. There were many types of nurse's power, tactics and various patient's responses about them. 1) Types of nurse's power to patients were giving information, controling environment, helping for cure, emotional support, and performing discretion. 2) Nurse's tatics for performing power were positive tactics neutral tactics, and negative tactics. 3) Patient's responses were appeared as compliance and noncompliance. Compliance were agreeing. taking nurse's advice, trusting, understanding, being admitted, exposuring himself, and appreciating. 3. There were types of nurse's power and performing tactics. 1) Types of power to a doctor were advice, informing, demanding and mediation. 2) Performings of tactics to a doctor were positive tactics, neutral tactics, and negative tactics. 3) Doctor's responses were appeared as accepting and unaccepting. Acceptings were taking in and appreciating, and unacceptings were denying nurse's advice and authoritative. 4. There were types of nurse's power and tactics about administrative workers and medical technicians and responses about them. 1) Types of power about administrative workers and medical technicians were suggestions and demands. 2) Power performings tactics were positive tactics.neutral tactics, and negative tactics. 3) Responses of administrative workers and medical technicians about nurse's power performing were appeared appeared as accepting and unacce pting. Acceptings were taking in, and unacceptings were denying. Therefore, it can be said that types of nurse's power and performing tactics on nursing practice and nurse's power based on responses of a patient, a doctor, an administrative worker, and a medical technicians are power or influence for agreeing, taking advice, trusting, understanding, exposuring himself, appreciating, and taking in to objects. The results of this study helped to understand nurse's power. I expect that this study will improve nure's power by using expert power, referent power, and legitimate power effectively among powers acmpanied with the origin and that nurses make ef-ort to improve professional knowledge and human nature so that they use this study as a chance to develope expert nursing practice.

• Journal of The Korean Association For Science Education
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• v.18 no.2
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• pp.233-243
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• 1998

Many science educators concern about the problems of assessment using paper & pencil test. Performance assessment is believed to be a very promising alternatives to traditional assessment. Portfolio assessment, a kind of performance assessment, has many desirable characteristics to foster students' creativity and increase students' responsibility for their own learning. However few research study has been dealt with this assessment method and few teacher adopts this method in science class. The characteristics and structures of portfolio assessment were explored by reviewing related literatures. The appropriate portfolio assessment was designed based on the results of exploration. For our primary science class, general and specific objectives are needed, depending on the nature of the instructional topics. The children's evidences for portfolio may be limited in their forms because of insufficient learning materials and reproducing facilities in classrooms. Large portions of children's evidence should be collected during class hours to reduce burdens of children. The evaluation criteria may be holistic rather than analytical because of large class size. Portfolio assessment will bring about many changes in primary science classes. Students' have more responsibility in science learning. Teachers will focus major instructional objectives, and concern more about students' meaningful learning. Although portfolio assessment requires more work to teachers and children it could be applicable to our science classroom.

• The Journal of Information Systems
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• v.27 no.1
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• pp.153-169
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• 2018

Purpose Since human brains catch images faster than texts or numbers, infographics has been widely used in business in the form of "information dashboard" to enhance the efficiency of decision-making. Groupware, however, has neglected the adoption and use of infographics, in particular, in the idea generation process. Given that an overall performance of groupware-based idea generation is no better than that of the (paper-and-pencil-based) Nominal Group Technique, Jung et al. (2010) adopted the notion of infographics in the form of performance feedback to solve the productivity paradox. With the consistent results, which demonstrate beneficial effects of infographics on performance enhancement, an interesting observation that groups with the bar chart treatment performed better than groups with the dot chart treatment was made. The main purpose of this study was to find if there were a performance consistency between the outcomes from the previous study and the outcomes from the current study. Design/methodology/approach In experiment 1, we employed the same system used in the previous study (i.e., Jung et al., 2010). As individuals' contributions accumulated, the mechanism visually displayed individuals' performances two-dimensionally in the form of a bar chart or a dot chart. Then, we compared the performance outcomes from this study to the outcomes from previous study (i.e., Jung et al., 2010). In experiment 2, we modified the performance graph to test the effect of "playfulness" on performance by converting dots to car images. Then, we compared the performance outcome from experiment 2 to the outcomes from experiment 1. Findings Just like our interesting (and unexpected) finding in Jung et al.'s study (2010), the outcome confirmed a consistent superior performance of a bar chart. This implies that a bar chart is a better choice when stimulating performance with a visual aid in the context of groupware-based idea generation. Although a bar chart was criticized in a way that errors of length-area judgments are 40 ~ 250% greater than those of positional judgments along a common scale, such illusion turned out to be facilitating upward performance comparison better. Regarding Experiment 2, the outcome showed that the revised-dot graph is as good as the bar graph in terms of quantity and quality score of ideas. We attribute the performance enhancement of the resized-dot to the interaction between the motivational characteristic and the situational characteristic of playfulness because individuals in the revised-dot graph treatment performed better than individuals in the dot graph treatment. Given the order of performance (Bar >= Revised Dot > Dot) that the revised-dot treatment performed the same as (or lower than) the bar treatment, an additional research is warranted to reach to a consistent outcome.

• Education of Primary School Mathematics
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• v.14 no.1
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• pp.13-26
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• 2011

The purpose of this research is to analyze geometrical level and the justification process in the proofs of construction by mathematically gifted elementary students. Justification is one of crucial aspect in geometry learning. However, justification is considered as a difficult domain in geometry due to overemphasizing deductive justification. Therefore, researchers used construction with which the students could reveal their justification processes. We also investigated geometrical thought of the mathematically gifted students based on van Hieles's Theory. We analyzed intellectual of the justification process in geometric construction by the mathematically gifted students. 18 mathematically gifted students showed their justification processes when they were explaining their mathematical reasoning in construction. Also, students used the GSP program in some lessons and at home and tested students' geometric levels using the van Hieles's theory. However, we used pencil and paper worksheets for the analyses. The findings show that the levels of van Hieles's geometric thinking of the most gifted students were on from 2 to 3. In the process of justification, they used cut and paste strategies and also used concrete numbers and recalled the previous learning experience. Most of them did not show original ideas of justification during their proofs. We need to use a more sophisticative tasks and approaches so that we can lead gifted students to produce a more creative thinking.

• Journal of Educational Research in Mathematics
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• v.18 no.1
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• pp.103-121
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• 2008

The primary purpose of this study was to gather knowledge about $5^{th},\;6^{th},\;and\;7^{th}$ graders' proportional reasoning ability by investigating their reactions and use of strategies when encounting proportional or nonproportional problems, and then to raise issues concerning instructional methods related to proportion. A descriptive study through pencil-and-paper tests was conducted. The tests consisted of 12 questions, which included 8 proportional questions and 4 nonproportional questions. The following conclusions were drawn from the results obtained in this study. First, for a deeper understanding of the ratio, textbooks should treat numerical comparison problems and qualitative prediction and comparison problems together with missing-value problems. Second, when solving missing-value problems, students correctly answered direct-proportion questions but failed to correctly answer inverse-proportion questions. This result highlights the need for a more intensive curriculum to handle inverse-proportion. In particular, students need to experience inverse-relationships more often. Third, qualitative reasoning tends to be a more general norm than quantitative reasoning. Moreover, the former could be the cornerstone of proportional reasoning, and for this reason, qualitative reasoning should be emphasized before proportional reasoning. Forth, when dealing with nonproportional problems about 34% of students made proportional errors because they focused on numerical structure instead of comprehending the overall relationship. In order to overcome such errors, qualitative reasoning should be emphasized. Before solving proportional problems, students must be enriched by experiences that include dealing with direct and inverse proportion problems as well as nonproportional situational problems. This will result in the ability to accurately recognize a proportional situation.

• Journal of The Korean Association For Science Education
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• v.21 no.1
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• pp.76-88
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• 2001

This study explored people's accuracy and methods of estimating some base physical quantities, i.e. length, mass, time and temperature. A total of 40 members, ranging from freshmen to professors, of a physics education department of a local university were asked to make two different kinds of estimations, intuitive and operational, on two sets of objects. For intuitive estimation, they were asked to make estimations on four given objects (length - wood chopsticks, mass - rubber eraser, time electric fan, temperature - water in a cup) as soon as they faced with the objects, usually within a few seconds of seeing. For operational estimation, they were allowed to make estimations on a different set of objects (length - plastic rod, mass - lock, time - simple pendulum, temperature - water in a cup) with enough time and they could apply various available methods (e.g. using pencil to estimate the object's length, counting their own pulse rate to estimate time) for the estimation. The findings of this study can be summarized as follows: (1) for length, mass and temperature the intuitive estimations were better performed while for the time estimation the result was the reverse; (2) there was no positive relationship between the amount of physics experience and the accuracy of the estimation; (3) in general, people's accuracy of the length estimation was best performed while their mass estimation was worst performed; (4) people used their own various methods for estimation, esp. using nearby objects around them and applying mental units which have convenient values (e.g. 30cm, 50cm, 1kg, 1 Keun, 1 second).

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.5 no.1
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• pp.162-171
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• 1994

Objects : This study was carried out to develop the Korean form of Leyton Obsessional Inventory-Child Version(LOI-CV) designed to assess the obsessive compulsive symptoms in children and adolescents. The LOI-CV was modified into a paper-and-pencil form in order to administer it to group. Methods : We applied the Korean form LOI-CV to 127 elementary, middle and high school children, and retest it to 82 children with 3 weeks interval. Together with LOI-CV, Korean form of SCL-90-R which had been proved its reliability and validity, were administered to the all subjects for examining of concurrent validity. And then we examined whether this scale discriminates between obsessive patients, psychiatric controls and normal controls in the level of obsessive symptoms. Results : Test-retest reliability, internal consistency were very satisfactory. Concurrent validity with SCL-90-R was moderate level. And obsessive patients was scored significantly higher than psychiatric and normal controls in the level of obsessive symptoms. In factor analysis, items are clustered to 5 factors. In the global obsessive symptom, obsessive scores of female elimentary school students were higher than that of male students. Conclusions : These results indicate that the Korean form of LOI-CV is reliable and valid self-rating scale to assess the obsessive-compulsive symptoms in Korean children and adolescents. Author suggests that future research is needed for Korean version standardization study in normal and clinic-refered population.