• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.86-94
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• 2020

Purpose: The purpose of this study is to compare the volume stability depending on the mixing methods and storage time for the conventional alginate and extended-pour alginate. Materials and methods: An arch-shaped metal model was fabricated, and one conventional alginate and two extended-pour alginates were used to take impressions using different mixing methods (hand and automatic). 120 impressions were taken (40 per each alginate) and stone models were made in accordance with the different storage times (immediate, 2 days, 5 days, and 6 days). The models were scanned with a 3D table scanner and dimensional change was measured by superimposing the scan data. Using SAS 9.4 (SAS Institute Inc., Cary, NC, USA), the general linear model and Tukey's post hoc test was conducted for statistical analysis (P<.001). Results: There was no statistically significant difference in the dimensional accuracy between two mixing methods, and the volume change was minimum when the stone was poured immediately in all groups. Dimensional accuracy showed a statistically significant difference between groups after 2 days of storage, and extended-pour alginate showed higher accuracy after 5 days of storage comparing to conventional one. Large amounts of volume change were showed at 2 - 5 days for conventional alginate and at 5 - 6 days for extended pour alginate. Conclusion: The mixing method of alginate does not affect volume stability. Although extended-pour alginate has better volume stability than conventional alginate for a long time, it is recommended to pour stone as soon as possible.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.569-575
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• 1988

Storage stabilities of ramyons fried in palm oil and beef tallow with added antioxidants and their synergists were investigated by comparing the changes in physicochemical parameters and n-hexanal concentrations of oils extracted from ramyons during storage. Ramyons fried in palm oil and beef tallow with added ${\delta}-tocopherol$ $({\delta}-toc)$ showed an enhanced storage stabilities when compared to those fried in the oils with ${\alpha}-tocopherol$ $({\alpha}-toc)$. Ascorbyl palmitate was found to be a better synergist than citric acid for the antioxidant activity of both ${\delta}-toc\;and\;{\alpha}-toc$. Phenolic antioxidants gave a better storage stability than tocopherol when ramyon was fried in beef tallow, while a mixture of BHA and BHT gave an inferior storage stability than${\alpha}-toc$ when ramyon was fried in palm oil. The effectiveness of the antioxidants tested on storage stability of stored ramyon had a close relationship to the n-hexanal concentration. On the other hand, the paramenters such as peroxide value, carbonly value, and conjugated diene concentration showed inconsistency during the course of the storage experiment.

• Journal of the Korean Electrochemical Society
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• v.13 no.3
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• pp.211-216
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• 2010

Boron trifluoride lithium methacrylate ($BF_3$LiMA)-based gel polymer electrolytes (GPEs) were synthesized with various $BF_3$LiMA concentration to elucidate the effect on ionic conductivity and electrochemical stability by a AC impedance and linear sweep voltammetry (LSV). As a result, the highest ionic conductivity reached $5.3{\times}10^{-4}Scm^{-1}$ at $25^{\circ}C$ was obtained for 4 wt% of $BF_3$LiMA. Furthermore, high electrochemical stability up to 4.3 V of the $BF_3$LiMA-based GPE was observed in LSV measurement since the counter anion was immobilized in this self-doped system. On the other hand, it was assumed that there was a rapid decomposition of electrolytes on a lithium metal electrode which results in a high solid electrolyte interface (SEI) resistance. However, a high stability toward graphite or lithium cobalt oxide (LCO) electrode thereby a low SEI resistance was observed from the AC impedance measurement as a function of storage time at $25^{\circ}C$. Consequently, the high ionic conductivity, good electrochemical stability and the good interfacial compatibility with graphite and LCO were achieved in $BF_3$LiMA-based GPE.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.3
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• pp.76-88
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• 2024

A significant cause of fall or overturning accidents in the construction industry, including landscaping construction and management, is work at heights using portable ladders. Portable ladders are classified as A-type or triangular support ladders depending on the number of supporting leg and support conditions. The tripod mobile ladder, which supports itself with only three supporting legs, is unstable and more prone to overturning compared to the A type ladders. Therefore, using the specifications of the tripod mobile ladder and the stability regulations of EN131-Part 7, overturning and resistance moment calculation formulas were derived for all directions in which overturning could occur. The moments calculated using these equations, and the overturning stability in each direction were evaluated. According to the calculation results, although there are differences depending on the direction, most are unstable for overturning at 8 or more steps. Based on these results, this study proposed measures to increase the moment of resistance by changing the weight, depth, and width, and using outriggers to ensure stability against the overturning of ladder. However, when changing the specifications of these measures, the size increases are excessive and the applicability is insufficient. On the other hand, outriggers are an applicable measure as they can ensure stability against overturning with only a minimum expansion length.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.333-346
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• 2014

If we want to analyze the motion of a body in fluid, we should use rigid-body dynamics and fluid dynamics together. Even if the rigid-body and fluid dynamics are each self-consistent, there arises the problem of self-similar structure in the equation of motion when the two dynamics are coupled with each other. When the added mass is greater than the mass of a body, the calculated motion is divergent because of its self-similar structure. This study showed that the above problem is an inherent problem. This problem of self-similar structure may arise in the equation of motion in which the fluid dynamic forces are treated as external forces on the right hand side of the equation. A reconfiguration technique for the equation of motion using pseudo-added-mass was proposed to resolve the self-similar structure problem; specifically for the case when the fluid force is expressed by integration of the fluid pressure.

• The Korean Journal of Health Service Management
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• v.9 no.3
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• pp.57-67
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• 2015

Objectives : This study has analyzed the relationship between DEA efficiency of costs-patient revenues, productivity per value added and management performance in mental hospitals. Methods : The relationship between DEA efficiency of costs-patient revenues, the productivity per value added and management performance were conducted with correlation analysis and logistic regression. Results : The DEA efficiency of costs-patient revenues had a significant causal relationship with the value added ratio to gross revenue indexing productivity per value added. On the other hand, it was revealed that the operating margin indexing management performance had a slightly significant causal relation with DEA efficiency of costs-patient revenues. Conclusions : The material costs should be focused on the management stability of mental hospitals, and known to the desirable management orientation for the higher efficiency of costs-patient revenues.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.232-232
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• 2009

In this paper, we investigated the sensitivity characteristics of $Bi_{12}BiO_{20}$ (BSO) voltage transformer (VT) by utilizing optical output measured according to the variation of ambient temperature and applied voltage. Fabricated BSO VT slightly showed the decrease of the accuracy in range of from $-20^{\circ}C$ to $50^{\circ}C$, on the other hand, the variation of the optical output result was not observed at the variation of applied voltage. We could finally confirm the temperature stability, applied voltage range, and the possibility that BSO could be applied for optical sensors in GIS system.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.9
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• pp.757-763
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• 2002

A newly designed haptic interface enables an operator to control a remote robot precisely. It transmits position information to the remote robot and feeds back the interaction force from it. A control algorithm of haptic interface has been studied to improve the robustness and stability to uncertain dynamic environments with a proposed contact dynamic model that incorporates human hand dynamics. A simplified hybrid parallel robot dynamic model fur a 6 DOF haptic device was proposed to from a real time control system, which does not include nonlinear components. LQC/LTR scheme was adopted in this paper for the compensation of un-modeled dynamics. The recovery of the farce from the remote robot at the haptic interface was demonstrated through the experiments.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1258-1261
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• 2004

Degradation phenomenon in the low-temperature polysilicon (LTPS) thin-film transistors (TFTs) with different junction structures was investigated. A gate-overlapped lightly doped drain (GOLDD) structure showed better hot-carrier stress (HCS) stability than a conventional LDD one. On the other hand, high drain current stress (HDCS) at $V_{gs}$ = $V_{ds}$ conditions caused much severe device degradation in the GOLDD structure because of its higher current level resulting in the higher applied power. It is suggested that self-heating-induced mobility degradation in the GOLDD TFFs be suppressed for using this structure in short-channel devices.

• BMB Reports
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• v.43 no.8
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• pp.524-529
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• 2010

Glucocorticoids (GCs) are useful drugs for the treatment of various diseases, but their use for prolonged periods can cause severe side effects such as osteoporosis. GCs have a direct effect on bone cells, where they can arrest bone formation, in part through the inhibition of osteoblast. On the other hand, GCs potently suppress osteoclast resorptive activity by disrupting its cytoskeleton based on the inhibition of RhoA, Rac and Vav3 in response to macrophage colony-stimulating factor. GCs also interfere with microtubule distribution and stability, which are critical for cytoskeletal organization in osteoclasts. Thus, GCs inhibit microtubule-dependent cytoskeletal organization in osteoclasts, which, in the context of bone remodeling, further dampens bone formation.