• Communications of Mathematical Education
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• v.34 no.3
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• pp.325-354
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• 2020

This study utilized longitudinal data from the 2013 year (Secondary Middle School) to 2017 year (Secondary High School) of the Seoul Education Termination Study. Using the latent growth model and the piecewise growth model, we investigated the changes in mathematics academic achievement, internal factors(self-concept, self-control, self-assessment of life satisfaction), and external factors(school climate, guardians) as students' grades increased, and examined whether internal factors and external factors influence the changes in mathematics academic achievement. We examined whether internal and external factors influence the change in academic achievement. As a result of analysis, it was found that mathematics academic achievement remained unchanged from the first grade of middle school to the second grade of middle school, and steadily increased from the second grade of middle school to the first grade of high school, and then decreased slightly in the second grade of high school. The internal and external factors had little change. It has been found that self-concept, self-control as internal factors, and school climate as external factors influence changes in mathematics academic achievement.

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.94-108
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• 2021

This study is to identify the internal and external factors of a company that can affect the rate of change in the inventory turnover ratio. In addition, by appropriately managing or responding to these factors, changes in the inventory turnover ratio do not occur abruptly, so that the company's business and financial performance can be improved. To confirm this, factors such as gross profit margin, cash flow volatility, advertising expenses, inflation, exchange rate rise, and leading economic index were selected, and these factors were predicted to affect the change rate of inventory turnover. Data of 85,878 companies were obtained from domestic securities listings, KOSDAQ listings, and externally audited companies, and multiple regression analysis was performed using the data. Gross profit margin and cash flow volatility have a significant positive (+) effect, advertising expenses have a negative (-) significant effect, and inflation and exchange rate rises have a negative (-) significant effect. As an influence, the leading economic index was tested to have a significant positive (+) effect. Through this, it is suggested that manufacturing companies can improve their business performance and achieve operational efficiency by well understanding and appropriately managing factors that can affect the change rate of inventory turnover.

• PNF and Movement
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• v.14 no.1
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• pp.1-6
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• 2016

Purpose: The purpose of this study was to analyze the effects of proprioceptive neuromuscular facilitation (PNF) patterns on electromyography (EMG) activity in the rectus abdominis, internal abdominal oblique, external abdominal oblique, and erector spinae according to position changes. Methods: Ten healthy adults volunteered to participate in the study. The subjects were required to complete exercises that followed two PNF extremity patterns, namely, an upper extremity extension-adduction-internal rotation pattern and a lower extremity flexion-adduction-external rotation pattern. The exercises were applied in the supine, side-lying, and sitting positions. Repeated measure one-way ANOVA and post-hoc Bonferroni correction were used to determine the influence of the patterns on muscle activity for each muscle, and descriptive statistics were then used to determine the local/global muscle ratios. Results: The upper extremity pattern had a significant effect on the rectus abdominis and erector spinae in the supine position, and on the internal oblique and external oblique in the sitting position (p<0.05). The median value for the internal oblique/rectus abdominis showed a high ratio of 2.05, and a high ratio of 1.01 was shown for the internal oblique/external oblique in the sitting position. The lower extremity pattern had a significant effect on the rectus abdominis in the side-lying position and on the internal oblique, external oblique, and erector spinae in the sitting position (p<0.05). The median value for the internal oblique/rectus abdominis showed a high ratio of 2.83 in the sitting position and a high ratio of 1.30 for the internal oblique/external oblique in the side-lying position. Conclusion: The PNF pattern increases local muscle activation in an unstable position. Therefore, when the pattern is used for intervention purposes, trunk stability and varied position changes should be taken into account.

• Management & Information Systems Review
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• v.7
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• pp.141-168
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• 2001

The causes that the transparency of Korean accounting information was rated low, a short supply of faithful and transparent accounting information from the limitation of external audit environment must be pointed out. Purpose of the external audit is a expression of the auditors about that financial statements an enterprise made public were appropriately drew up in accordance with the corporate accounting principles from important point of view. Analysis of the audit opinion and so fourth according to 6,541 individual audit reports and introduced to the bill securities forward committee as a subject of external audit according to the raw of corporation external audit show that considerable change to the contents of audit report. This show as it is that uncertainty of future that is now being faced by our enterprise, because corporation which present audit reports since 1997 because of enterprise dishonor and contents of existence probability as a continued enterprise following to general economic crisis after 1998 occupy important position in special matters of audit report. Also, increase in special matters is due to application of the corporate accounting principles revised on December 11, 1998. In 1999, audit opinion under limitation(limitation, incongruity and rejecting opinion) increased greatly according to existence doubt as a continued enterprise, and this is the consequence of strengthening audit to the continues enterprise because of limited enterprise dishonor according to the stagnancy of business activities after 1997. Now financial supervisory service put in effect electromagnetic public announcement system about a project report of listed corporation (including an audit report) keeping pace with a documentary public announcement system as first phase since 1999 and expand to the unlisted corporation from 2000. As electromagnetic public announcement of public announcement documents including audit documents of external audit subject get a duty, approach of external user to the accounting information will be easier. Fixation of this system will make deep and wide analysis to the audit opinion, and this will draw up a plan to reconsider confidence of accounting information.

• The Korean Journal of Pharmacology
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• v.18 no.2
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• pp.89-102
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• 1982

The $Na^+-and\;K^+-induced\;Ca^{++}$ release was measured isotopically by millipore filter technique in pig heart mitochondria. With EGTA-quenching technique, the characteristics of mitochondrial $Ca^{++}-pool$ and the sources of $Ca^{++}$ released from mitochondria by $Na^+\;or\;K^+$ were analyzed. The mitochondrial $Ca^{++}-pool$ could be distinctly divided into two components: internal and external ones which were represented either by uptake through inner membrane, or by energy independent passive binding to external surface of mitochondria, respectively. In energized mitochondria, a large portion of $Ca^{++}$was transported into internal pool with little external binding, while in de-enerigzed state, a large portion of transported $Ca^{++}$ existed in the external pool with limited amount of $Ca^{++}$ in the internal pool which was possibly transported through the $Ca^{++}-carrier$ present in the inner membrane. $Na^+$ induced the $Ca^{++}$ release from both internal pool and external pool and external binding pool of mitochondria. In contrast, $K^+$ did not affect $Ca^{++}$ of the internal pool, but, displaced $Ca^{++}$ bound to external surface of the mitochondria. When the $Ca^{++}-reuptake$ was blocked by EGTA, the $Ca^{++}$ release from the internal pool by $Na^+$ was rapid; the rate of $Ca^{++}-efflux$ appeared to be a function of $[Na^+]^2$ and about 8mM $Na^+$ was required to elicit half-maximal velocity of $Ca^{++}-efflux$. So it was revealed that $Ca^{++}-efflux$ velocity was particulary sensitive to small changes of the $Na^+$ concentration in physiological range. Energy independent $Ca^{++}-binding$ sites of mitochondrial external surface showed unique characteristics. The total number of external $Ca^{++}-binding$ sites of pig heart mitochondria was 29 nmoles per mg protein and the dissociation constant(Kd) was $34{\mu}M$. The $Ca^{++}-binding$ to the external sites seemed to be competitively inhibited by $Na^+\;and\;K^+$; the inhibition constant(Ki) were 9.7 mM and 7.1 mM respectively. Considering the intracellular ion concentrations and large proportion of $Ca^{++}$ uptake in energized mitochondria, the external $Ca^{++}-binding$ pool of the mitochondria did not seem to play a significant role on the regulation of intracellular free $Ca^{++}$ concentration. From this experiment, it was suggested that a small change of intracellular free $Na^+$ concentration might play a role on regulation of free $Ca^{++}$ concentration in cardiac cell by influencing $Ca^{++}-efflux$ from the internal pool of mitochondria.

• The Transactions of the Korea Information Processing Society
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• v.7 no.7
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• pp.2264-2271
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• 2000

• Journal of Korean Medical Ki-Gong Academy
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• v.7 no.1
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• pp.45-60
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• 2003

• The Journal of Korean Medicine
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• v.25 no.3
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• pp.137-148
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• 2004

Objectives : To study change of external dermal formation, change of leukocytes in vasculature, change of lipid formation in stratum corneum and distribution of ceramide through administering Sihocheonggan-san (SC) extract on to the control (CON). This study was done through forcing injury to mice's back skin which have lipid protection formation in stratum corneum. Materials and Methods : The CON to which damage was caused intentionally using the external application on the mice's back skin used the SC. The change of leukocytes in vasculature were identified through optima 5.2 and Student's t-test and the results were made into a dermal formation graph. Results : After dispensing SC extract into the CON, dermal injury was decreased. Especially, recover of lipid protection formation, which includes lipid and ceramide in stratum corneum suppressing acute inflammation that some factors are PKC, TNF-α, IL-12B which controlled the secretion of relating inflammatory cytokine, also went onto decrease of angiogenesis, and a decrease of degranulated mast cells was noted. In addition, the decrease of epithelial injury also caused the growth of cells to decrease in stratum basale and cytoclasis. In the vasculature, the leukocytes were also decreased and it could relate to decrease in CON. Conclusions : SC has effect on CON suppressing the dermal injury through recovering of lipid protection formation in stratum corneum.

• Journal of the Korean housing association
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• v.26 no.3
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• pp.55-64
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• 2015

This study is conducted to understand the social value of Nakwon building, which has been instilled in the architecture of the building, through an analysis of formative elements unique to the center. The architectural characteristics of Nakwon building have been formed over a long period of time in relation with its surroundings and social change. Before looking into the formation of the center, this study investigates the street network planning of downtown. The street network was planned to expand in a north-south direction in order to accommodate a future increase of traffic volume as a result of industrialization and a population increase in downtown. This was manifested in expanding Samilro Street which passes through the lower part of Nakwon building, as well as in forming the architecture of the center. That is, the center has formed a symbiotic relationship with its surrounding areas, sharing space with them. The interior of the center seems to have an independent form while keeping a relationship with its external format, but it is seeking change internally in response to external change. Interior space has been departmentalized over time since its initial establishment, and the internal traffic has also been subdivided accordingly. This is attributable to the fact that social change in the neighboring areas affected the formation of Nakwon building, and that in turn contributed to forming the unique characteristics of the building. Nakwon building is one of the deteriorated buildings in downtown Seoul. However, it was built out of social need to share space within the city, and it has been changed according to social need for the 'distribution of space within the building.

• Journal of Sensor Science and Technology
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• v.28 no.3
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• pp.198-204
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• 2019

In this study, we propose a wearable force sensor using 3D printed mold and liquid metal. Liquid metal, such as Galinstan, is one of the promising functional materials in stretchable electronics known for its intrinsic mechanical and electronic properties. The proposed soft force sensor measures the external force by the resistance change caused by the cross-sectional area change. Fused deposition modeling-based 3D printing is a simple and cost-effective fabrication of resilient elastomers using liquid metal. Using a 3D printed microchannel mold, 3D multichannel Galinstan microchannels were fabricated with a serpentine structure for signal stability because it is important to maintain the sensitivity of the sensor even in various mechanical deformations. We performed various electro-mechanical tests for performance characterization and verified the signal stability while stretching and bending. The proposed sensor exhibited good signal stability under 100% longitudinal strain, and the resistance change ranged within 5% of the initial value. We attached the proposed sensor on the finger joint and evaluated the signal change during various finger movements and the application of external forces.