• The Korea Journal of Herbology
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• v.38 no.5
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• pp.31-37
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• 2023

Objective : This study was conducted to investigate the muscle-improving and therapeutic effects of Boehmeria platanifolia (BP) in a mouse model of dexamethasone-induced muscle atrophy. Methods : Muscle atrophy was induced in C57BL/6 mice by intraperitoneal administration of dexamethasone for 12 days. BP extract was administered orally at doses of 100 mg/kg and 200 mg/kg for 19 days, starting 7 days before the intraperitoneal administration of dexamethasone. Mice were weighed during the experimental period, and muscle strength and muscle weight were measured at the end of the experiment. The gastrocnemius (GASTROC) muscles of mice were isolated and the cross-sectional area (CSA) of the muscle fibers was measured after H&E staining. Results : Dexamethasone-induced muscle atrophy mice had a decrease in body weight compared to normal mice, and BP-administrated mice did not show significant change in body weight compared with a control group. Muscle strength in mice with induced muscle atrophy was reduced compared to normal and significantly increased with BP administration and positive control. In addition, the weight of the quadriceps (QUAD) muscle and fiber size of the GASTROC muscle, which was reduced in sarcopenia-induced mice, was increased by BP. Conclusion : BP extract increased muscle strength, muscle weight, and muscle fiber size in dexamethasone-induced muscle atrophy mice. This suggests that the efficacy of BP extracts in improving muscle strength and preventing and treating sarcopenia may be beneficial for the development of potential therapeutic or functional products.

• Journal of information and communication convergence engineering
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• v.13 no.1
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• pp.7-14
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• 2015

In a multi-hop wireless network, connectivity is determined by the link that is established by the receiving signal strength computed by subtracting the path loss from the transmission power. Two path loss models are commonly used in research, namely two-ray ground and shadow fading, which determine the receiving signal strength and affect the link quality. Link quality is one of the key factors that affect network performance. In general, network performance improves with better link quality in a wireless network. In this study, we measure the network connectivity and performance in a shadow fading path loss model, and our observation shows that both are severely degraded in this path loss model. To improve network performance, we propose power control schemes utilizing link quality to identify the set of nodes required to adjust the transmission power in order to improve the network throughput in both homogeneous and heterogeneous multi-hop wireless networks. Numerical studies to evaluate the proposed schemes are presented and compared.

• IE interfaces
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• v.12 no.1
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• pp.150-157
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• 1999

Mini-Mill process has been recently in operation at Pohang steel company, which enables more flexible steel coil production on customer demands. The effects of process parameters in Mini-Mill process need to be analyzed not only to make the process stable but also to improve product quality. This work aims to develop a regression model of Mini-Mill process using accumulated product data such that the process parameter effects on product tensile strength may be analyzed. The analysis shows that tensile strength is influenced mainly by the amount of components such as carbon, manganese, silicon, and sulfur. The effect of temperature is shown to be small. It is concluded that control of the components is much more responsible for both meeting the target and reducing the variation of the product tensile strength. Heat treatment is more useful in compensating tensile strength variations due to thickness differences and improving workability and other quality characteristics. More work is necessary for establishing regression expressions of the process that is reliable and accurate enough to dispense with the off-line inspection of the product tensile strength.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.325-342
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• 2020

The current study is focused on the evaluation of the ultimate strength of stiffened panels found in ship hull structures that are subjected to combined uniaxial thrust, in-plane and out-of-plane bending moments. This loading condition, which is in general ignored when performing buckling checks, applies to representative control geometries (stiffener with attached plating) as a consequence of the linearly varying normal stresses along the ship's depth induced by the hull-girder vertical bending moment. The problem is generalized by introducing a non-uniform thrust described by a displacement ratio and rotation angle and by introducing the slenderness ratios, within the practical range of interest. The formed design space is explored through methods sourcing from Design of Experiments and by applying non-linear finite element procedures. Surrogate empirical models have been constructed through regression analysis and Response Surface Methods. An additional empirical model is provided to the literature for predicting the ultimate strength under uniaxial thrust. The numerical experimentation has shown that is a significant influence on the ultimate strength of stiffened panels as the thrust non-uniformity increases.

• The Journal of Society for e-Business Studies
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• v.11 no.1
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• pp.25-52
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• 2006

This study focuses on customer perception of security control under Internet banking environment Internet banking customers' understanding of security control is insufficient. They are not fully aware of security technologies for Internet banking. Moreover, they cannot know which control is implemented and maintained on an Internet banking site when visiting the site. This study, therefore, attempts to find the impact of customer perception of security control on Internet banking acceptance. The research model is based on the TAM (Technology Acceptance Model), and introduces trust as an additional belief. Trust has been investigated in the marketing area, and begins to be focused in e-business area. A Web survey of Internet banking users collected 845 cases. Statistical analyses, using SEM (Structural Equation Modeling), partially supported the hypotheses that perceived strength of security control has an impact on three beliefs: trust, perceived usefulness, and perceived ease of use. We also verified the impact of these beliefs on attitude toward using, on behavioral intention to use, and on actual use. It is, therefore, verified that perceived strength of security control is a determinant of Internet banking acceptance.

• Structural Engineering and Mechanics
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• v.31 no.4
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• pp.423-437
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• 2009

In order to perform a step-by-step force-displacement response analysis or dynamic time-history analysis of large buildings with masonry infilled R/C frames, a continuous force-deformation model based on an equivalent strut approach is proposed for masonry infill panels containing openings. The model, which is applicable for degrading elements, can be implemented to replicate a wide range of monotonic force-displacement behaviour, resulting from different design and geometry, by varying the control parameters of the model. The control parameters of the proposed continuous model are determined using experimental data. The experimental program includes fifteen 1/3-scale, single-story, single-bay reinforced concrete frame specimens subjected to lateral cyclic loading. The parameters investigated include the shape, the size, the location of the opening and the infill compressive strength. The actual properties of the infill and henceforth the characteristics needed for the diagonal strut model are based on the assessment of its lateral resistance by the subtraction of the response of the bare frame from the response of the infilled frame.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.103-113
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• 1993

The purpose of this study was to evaluate the tensile bond strength of composite resin inlays according to the their internal surface treatment and types of luting cement and compared them with the conventional direct resin filling thchnique. Class II cavities were prepared in 50 extracted human molar teeth, and then equally divided into five groups. Group 1 : Cavities of control group were directly filled with P-50. Group 2 : Cavities of resin inlay group were luted with resin cement. Group 3 : Cavities of resin inlay group were luted with luting G-I cement. Group 4 : Cavities of resin inlay group were luted with resin cement after sandblasting. Group 5 : Cavities of resin inlay group were luted with luting G-I cement after sandblasting. All specimens were polished with same method and stored in normal saline for 24 hours before testing. An Universal Testing machine(Model No. AGS-100A, Shimadzu, Japan) was used to apply tensile loads in the vertical direction, and the force required for separation was recorded with a cross-head speed of 5mm/min and 100kg in full scale. The results were as follows : 1. The mean tensile bond strength was lowest in group luted with luting G-I cement, with measurements of $14.45{\pm}0.78(kg/cm^2)$ and highest in group luted with resin cement after sandblasting, with measurements of $49.6{\pm}2.74(kg/cm^2)$. 2. The tensile bond strength was greater in resin inlay groups luted with resin cement than in control group and resin inlay groups luted with luting G-I cement(P<0.05). 3. The tensile bond strength was lower in resin inlay groups luted with luting G-I cement than in control group(P<0.05). 4. The tensile bond strength was greater in resin inlay groups luted with resin cement or luting G-I cement after sandblasting than without that(P<0.05).

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.593-596
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• 1999

Steel fibers are added to concrete to improve energy absorption, impact resistance and apparent ductility, and to provide crack resistance and crack control. This study is to investigate the toughness index and post-crack equivalent tensile strength of steel fiber reinforced concrete properties on the load-deflection behaviors of the steel fiber reinforced concrete beam model specimens.

• Journal of the Korean Ceramic Society
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• v.24 no.4
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• pp.392-396
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• 1987

Pure barium titanate was sintered at $1340^{\circ}C$ for 2, 4, 8, 16 hr to control their grain size. The measurements of breakdown strength and partial discharge characteristics were performed under rising AC voltage(60Hz). With increase of sintering time, the average grain size was increased and breakdown strength was slightly decreased. Partial discharge in pores was observed under high voltage, and a model of dielectric break down in barium titanate ceramics is proposed.

• Journal of Korean Academy of Nursing
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• v.42 no.7
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• pp.1009-1018
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• 2012

Purpose: This study was done to evaluate effectiveness of home healthcare services (HHCS) specialized for elders who received spinal surgeries. Methods: A non-equivalent control group pre-post test quasi-experimental study was performed. HHCS was developed based on the Rice model of dynamic self-determination for self-care. For data collection, a control group (n=23) and an experimental group (n=23) were selected by matching age, BMI, pain, general characteristics and type of spine surgery. Measurement tools to evaluate uncertainty and knowledge were developed by the authors. The Numeric Rating Scale (NRS) and Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were used to evaluate pain levels. Muscular strength in the legs was measured using a digital muscle tester and tape ruler. Questionnaires were used to evaluate disability in performing ADL and psychological distress levels. Results: The experimental group showed significant decrease in uncertainty (p=.028), increased knowledge (p=.038), and partially decreased pain (p=.003-.331). Partial muscle strength increased significantly (p=.021-.644). Disability in performing ADL and psychological distress in the experimental group decreased significantly compared to control group (p=.002, p=.004). Conclusion: Results indicate HHCS is an efficient home care nursing program for these elders. Further experimental studies with larger samples are required to confirm effects of HHCS.