• Journal of the Korean Society of School Health
• /
• v.17 no.2
• /
• pp.107-114
• /
• 2004

Purpose: This descriptive study was conducted to compare the teaching status, utilization of the teaching materials, and the need to solve matters of sex education between the school health educators and teachers working in an elementary school in Busan. Method: 182 school health educators and 125 teachers participated in the research. Data was collected using a self-administered questionnaire, and analyzed by frequency and x2 -test using the SPSS WIN 10.0 Program. Results: While school health educators carried out most of the sex education in the extra curriculum and physical education class, teachers did in the regular curriculum and physical education class. Regarding the utilization of the teaching materials on sex education, although the majority of school health educators used the teacher's manual, only a few teachers used it. Most of the school health educators used the ICT teaching materials while only half of the teachers did. Regarding the methods to solve matters on sex education, school health educators responded that a sex-related subject should be combined with a health subject, and an independent sex-related subject was necessary. The teachers, however, responded that it was necessary to secure enough time for sex education, the sex-related subject combined with a health subject was necessary, and there is a need to designate a sex educator. Conclusion: School health educators utilized more teaching materials for sex education and suggested more active methods to solve matters related to sex education. Therefore, school health educators should be more active as sex educators, and the subject of sex education should be adopted as a regular course.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.11a
• /
• pp.49-53
• /
• 1996

Crystal structures of N $a_{x}$W $O_3$(0.5$\leq$x$\leq$1.0) were investigated. Transmission electron microscopy (TEM) studies indicate that there is an ordering of sodium ions when x=0.75. The direction of ordering is [110] and the wavelength of ordering is twice of the interplanar distance of (110) plane. It has been confirmed that a superlattice containing eight N $a_{0.75}$W $O_3$is the unit cell of ordered structure. In this unit cell, Na sites at (100) and ($\frac{1}{2}$$\frac{1}{2}$$\frac{1}{2}$) are vacant. The ordered phase was preserved after the annealing at $600^{\circ}C$ in the air. In reduced N $a_{x}$W $O_3$with x=0.5 and 1.0, extra phases were found to coexist with the partially ordered perovskite phase. After annealing at $600^{\circ}C$, theses phases were transformed into the phases found in calcined specimens.ens.s.

• Applied Chemistry for Engineering
• /
• v.31 no.6
• /
• pp.630-634
• /
• 2020

We developed a processing recipe to synthesize flexible polyurethane foam with a pore size of 335 ± 107 ㎛. The gelling reaction time was varied from 0 to 30 minutes and the physical properties of the foam were evaluated. The gelling reaction where the polypropylene glycol and tolylene 2,4-diisocyanate (TDI) were reacted to form urethane prepolymer, proceeded until a chemical blowing agent, deionized water, was introduced. Fourier transform infrared (FT-IR) spectra showed that the composition of the foam did not change but the foam height reached a peak value when the gelling reaction time was 10 minutes. We found that increasing the gelling time lessened the coalescence and helped the formation of cells. Lastly, the repeatability of polyurethane foam was confirmed by one-way analysis of variance (ANOVA) by synthesizing ten identical polyurethane foams under the same experimental conditions, including the gelling reaction time. Overall, the new time parameter in-between the gelling and blowing reactions will give extra stability in manufacturing identical polyurethane foams and can be applied to various polyurethane foam processes.

• Journal of Drive and Control
• /
• v.17 no.2
• /
• pp.1-8
• /
• 2020

Recently, industrial systems are becoming quicker and lighter to enable the reduction of energy consumption and increase productivity. So the latest systems are more flexible and rapid than the previous systems. But, with this improvement, another problem has emerged, such as the increase in residual vibration when a system is started or stopped. The input shaper is a command generation method that can remove residual vibration. It can provide a solution to the problem of residual vibration in industrial systems. However, it is difficult to generate the input shaper in high order systems, such as a typical industrial system because the input shaper is induced from the system's vibration characteristics. This study focused on the extra insensitivity shaper that can compensate for the system's modeling error such as input dynamics, and the high order's system affection. A genetic algorithm was deployed to adjust a vibration limitation for the extra insensitivity of the input shaper. A plant is a low damping system that includes one zero and a pole. The fitness functions are an error signal of the system's response with normalized frequency variations. Verification of the suggested system is satisfied by comparison between the zero vibration derivative input shaper's response and the suggested one.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.4
• /
• pp.392-402
• /
• 1997

The morphological traits of different types of primary trisomics(2n=28＋1) in durum wheat, Triticum durum var. hordeiforme(2n=28 AABB) were compared with disomics (2n=28) through the examination of reciprocal gene action on the extra chromosomes. However it was not easy to distinguish morphologically the trisomies containing A genome from those containing B genome. These results suggested that the chromosomal location of the major genes for some morphological traits exists on homoeologous chromosome. It is important that these results revealed the homoeology and linkage groups of both A and B genomes in durum wheat. These primary trisomies will be valuable materials for the trisomic analysis and genetic mapping on the chromosome of both A and B genomes in durum wheat. Furthermore, it must be useful for the evolutionary study of Triticum durum(AABB) and Triticum squarrosa(DD) by way of the ancester species of Triticum aesitivum(AABBDD).

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.873-878
• /
• 2008

Doosan Mecatec has developed alignment system for Organic Light-Emitting Diode (OLED) display production using large size substrate. In the present article, The alignment system between the substrate and the mask, which is a core technology for producing the OLED product using the fourth-generation substrate with $730{\times}920mm^2$ or more, will be described by dividing into a substrate loader, a magnet unit, a CCD camera, etc. The substrate loader is optimized through the simulation where the central portion of the substrate droops by about 1.5mm by clamping each of a long side (920mm direction) and a short side (730mm direction) thereof by 6 point and 4 point. A magnet unit using a sheet type of rubber magnet is constituted and a CCD camera model with the specifications capable of minimizing the errors between a clear image and the same image is selected. The system to which an upward evaporation technique of small molecular organic materials will be applied has been developed so that repeatability and position accuracy becomes ${\pm}1{\mu}m$ or less using an UVW type of stage. Also, the vision accuracy of the CCD camera becomes ${\pm}1{\mu}m$ or less and the align process TACT becomes 30sec. or less so that the final alignment accuracy between the substrate and the mask becomes ${\pm}3{\mu}m$ or less. In order to meet an extra-large glass substrate, an evaporation system using an extra-large AMOLED substrate has been developing through a vertical type of an alignment system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.41 no.6
• /
• pp.299-305
• /
• 2015

Objectives: This article describes our experience with neck dissection in 10 patients with oral squamous cell carcinoma. Materials and Methods: Between January 2007 and October 2009, 10 patients underwent primary surgery for the treatment of squamous cell carcinoma of the oral cavity. For patients with $N_0$ disease on clinical exam, selective neck dissection (SND [I-III]) was performed. In patients with palpable cervical metastases (N+), modified radical neck dissections were performed, except in one patient in whom SND (I-III) was performed. The histopathologic reports were reviewed to assess the surgical margins, the presence of extra-capsular spread, perineural invasion, and lymphatic invasion. Results: On histopathologic examination, positive soft tissue margins were found in three patients, and regional lymph node metastases were present in five of the ten patients. Perineural invasion was noted in five patients, and extra nodal spread was found in four patients. Regional recurrence was seen in two patients and loco-regional recurrence plus distant metastasis to the tibia was observed in one patient. During the study period, three patients died. Seven patients remain free of disease to date. Conclusion: Histopathological evaluation provides important and reliable information for disease staging, treatment planning, and prognosis. The philosophy of neck dissection is evolving rapidly with regard to the selectivity with which at-risk lymph node groups are removed. The sample size in the present study is small, thus, caution should be employed when interpreting these results.

• Korean Journal of Head & Neck Oncology
• /
• v.37 no.2
• /
• pp.33-41
• /
• 2021

Background/Objectives: Extra-nodal extension (ENE) is one of the strongest prognosticators in oral cancers. Here we tried to evaluate clinicopathological factors associated with the presence of ENE. Materials & Methods: We retrospectively analyzed clinical information of 120 patients who diagnosed with oral cancer and received curative surgery at our hospital from Mar 2012 to Apr 2020. We comparatively analyzed clinicopathological factors associated with the presence of lymph node (LN) metastasis and ENE, respectively. Results: Variable factors of primary tumor characteristics such as lymphovascular invasion, perineural invasion, largest diameter of tumor, depth of invasion and maximum standardized uptake value were significantly associated with the presence of cervical LN metastasis. The largest diameter of tumor was statistically significant also in multivariate analysis for predicting the LN metastasis. Meanwhile, the association between primary tumor characteristics and the presence of ENE were not statistically significant except the primary tumor size. Importantly, factors associated with LN characteristics including the maximum diameter and number of metastatic LNs were significantly associated with ENE. Conclusion: In this study, several factors affecting cervical LN metastasis and ENE in oral cancer patients were identified. The ENE seems to be influenced by the status of the metastatic LNs, such as the number of metastatic LNs, rather than the characteristics of the primary tumor itself.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.1
• /
• pp.42-47
• /
• 2010

Polymer insulating materials such as cross linked polyethylene (XLPE) are employed in electric cables used for extra high voltage. These materials can degrade due to chemical, mechanical and electric stress, possibly caused by voids, the presence of extrinsic materials and protrusions. Therefore, this study measured discharge patterns, discharge phase angle, quantity and occurrence frequency as well as changes in XLPE under different temperatures and applied voltages. To quantitatively analyze the irregular partial discharge patterns measured, the discharge patterns were examined using a statistical program. A three layer sample was fabricated, wherein the upper and lower layers were composed of non-void XLPE, while the middle layer was composed of an air void and copper particles. After heating to room temperature and $50^{\circ}C$ and $80^{\circ}C$ in silicone oil, partial discharge characteristics were studied by increasing the voltage from the inception voltage to the breakdown voltage. Partial discharge statistical analysis showed that when the K-means clustering was carried out at 9 kV to determine the void discharge characteristics, the amount discharged at low temperatures was small but when the temperature was increased to $80^{\circ}C$, the discharge amount increased to be 5.7 times more than that at room temperature because electric charge injection became easier. An analysis of the kurtosis and the skewness confirmed that positive and negative polarity had counterclockwise and clockwise clustering distribution, respectively. When 5 kV was applied to copper particles, the K-means was conducted as the temperature changed from $50^{\circ}C$ to $80^{\circ}C$. The amount of charge at a positive polarity increased 20.3% and the amount of charge at a negative polarity increased 54.9%. The clustering distribution of a positive polarity and negative polarity showed a straight line in the kurtosis and skewness analyses.

• School Mathematics
• /
• v.17 no.1
• /
• pp.79-98
• /
• 2015

The purpose of this study was to develop the elementary mathematics textbooks as a thematic approach, to suggest meaningful directions to future textbook development and curriculum development. For this study, we suggested mathematics textbooks of the three-themes, 'Healthy Life', 'Sustainable Life', 'Living-together Life', as multi-disciplinary, inter-disciplinary, and extra-disciplinary types. With the problems that employed thematic approaches, the post-achievement scores of experimental groups who used 'Healthy Life' and 'Sustainable Life' textbooks were meaningfully higher than those of control groups. However, the post-achievement scores of experimental groups who used 'Living-together Life' textbook were not meaningfully higher than those of control groups. The attitudes towards mathematics of all three experimental groups were meaningfully higher than those of control groups. After applications of elementary mathematics textbooks as a thematic approach, we need to develop related materials, to consider various grades, levels, regions for developing better mathematics textbooks.