• The Journal of the Korean dental association
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• v.51 no.12
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• pp.650-657
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• 2013

The aim of this study was to achieve healing of Peri-implantitis defects and hard tissue augmentation using a bovine-derived bone mineral on the defect site. Two patients were treated with the surgical approach. With a full muco-periosteal flap elevation, the implant surfaces were exposed and granulation tissue removed around the implant and between the threads. Each surface of the contaminated implant was prepared with the air-abrasive device(PerioFlow$^{(R)}$) for decontamination. Bovine-derived bone mineral(Bio-Oss collagen$^{(R)}$) was then used to fill the defects and muco-periosteal flaps sutured to achieve transmucosal healing. Radiographs and clinical photographs were taken before and after 6 months of healing and an estimate of bone fill was assessed. Within the limits of the present case report, a surgical approach in treatment of peri-implantitis defects using a collagen form of bovine bone mineral was visited. Although limited, the two cases showed the stability and biocompatibility of a bovine-derived bone mineral and effectiveness of air-abrasive device(PerioFlow$^{(R)}$) as a decontamination method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.4
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• pp.595-599
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• 2018

Interruption system with the transformer type superconducting fault current limiter(TSFCL) is proposed in this paper. The interruption system with a TSFCL is a technology that it maximizes the interruption function of a mechanical DC circuit breaker using a transformer and a superconducting fault current limiter. By a TSFCL, the system limits the fault current till the breakable current range in the fault state. Therefore, the fault current could be cut off by a mechanical DC circuit breaker. The Interruption system with a TSFCL were designed using PSCAD/EMTDC. In addition, the Interruption system with a TSFCL was applied to the DC test circuit to analyze characteristics of a current-limiting and a interruption operation. The simulation results showed that the Interruption system with a TSFCL interrupted the fault current in a stable when a fault occurred. Also, The current-limiting rate of the Interruption system with a TSFCL was approximately 69.55%, and the interruption time was less than 8 ms.

• Journal of the Korean Society of Combustion
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• v.14 no.1
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• pp.25-30
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• 2009

Propagation rates ($U_{edge}$) of various premixed, twin edge-flames were measured as a function of global strain rate ($\sigma$), mixture strength, and Lewis number (Le). Using a counterflow slot-jet burner with electrical heaters at each end, both advancing (positive $U_{edge}$) and retreating (negative $U_{edge}$) edge-flames can be studied as they propagate along the long dimension of the burner. Experimental results are presented for premixed methane/air twin flames in terms of the effects of $\sigma$ on $U_{edge}$. Both low-$\sigma$ and high-$\sigma$ extinction limits were discovered for all mixtures tested. As a result, the domain of edge-flame stability was obtained in terms of heat loss factor and normalized flame thickness, and comparison with the numerical result of other researchers was also made. For low ($CH_4/O_2/CO_2$) and high ($C_{3}H_{8}$/air) Lewis number cases, propagation rates clearly show a strong dependence on Le.

• Journal of the Korean Regional Science Association
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• v.6 no.1
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• pp.1-10
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• 1990

Regionalism has become a liability in Korea, hampering national harmony and political stability. The regionalism finds its roots in several centuries back in history. The traditional regionalism was based on the provincial differences in cultural and social characteristics, and behavioral mannerism. Therefore, the traditional regionalism should be regarded as benign and common as in many other countries in the world. The modern version of Korean regionalism seems to be founded on the "discriminatory" treatments of Honam provinces in economic policy and the resultant regional economic disparity during the last three decades. Many believe that such "discriminatory" policy had been enforced during the period of the "third" and "fourth" republics under the influence of the key government officials and presidents form the Southeastern provinces. Since the early 80s, many public investment projects have found its home in the Honam region with the consideration of regional balance and more equitable distribution. This paper attempts to elucidate on various causes of regional disparity amplified during the period of industrialization, and also presents the economic indices which demonstrate the impacts of the policy in narrowing the economic disparity among the regions in recent years. The paper also clarifies the limits of regional economic policy in achieving regional. balance and consequently social integrity. The last part of the paper attempts to clarify the effective domain of regional policy and the new direction of regionalism.cy and the new direction of regionalism.

• International Journal of High-Rise Buildings
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• v.1 no.4
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• pp.271-281
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• 2012

Tianjin Goldin Finance 117 tower has an architectural height of 597 m, total of 117 stories, and the coronation of having the highest structural roof of all the buildings under construction in China. Structural height-width ratio is approximately 9.5, exceeding the existing regulation code significantly. In order to satisfy earthquake and wind-resisting requirements, a structure consisting of a perimeter frame composed of mega composite columns, mega braces and transfer trusses and reinforced concrete core containing composite steel plate wall is adopted. Complemented by some of the new requirements from the latest Chinese building seismic design codes, design of the super high-rise building in high-intensity seismic area exhibits a number of new features and solutions to professional requirements in response spectrum selection, overall stiffness control, material and component type selection, seismic performance based design, mega-column design, anti-collapse and stability analysis as well as elastic-plastic time-history analysis. Furthermore, under the prerequisite of economic viability and a series of technical requirements prescribed by the expert review panel for high-rise buildings exceeding code limits, the design manages to overcome various structural challenges and realizes the intentions of the architect and the client.

• Advances in concrete construction
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• v.11 no.1
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• pp.1-9
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• 2021

This article discusses the issue of optimizing controller design issues, in which the artificial intelligence (AI) evolutionary bat (EB) optimization algorithm is combined with the fuzzy controller in the practical application of the building. The controller of the system design includes different sub-parts such as system initial condition parameters, EB optimal algorithm, fuzzy controller, stability analysis and sensor actuator. The advantage of the design is that for continuous systems with polytypic uncertainties, the integrated H2/H∞ robust output strategy with modified criterion is derived by asymptotically adjusting design parameters. Numerical verification of the time domain and the frequency domain shows that the novel system design provides precise prediction and control of the structural displacement response, which is necessary for the active control structure in the fuzzy model. Due to genetic algorithm (GA), we use a hierarchical conditions of the Hurwitz matrix test technique and the limits of average performance, Hierarchical Fitness Function Structure (HFFS). The dynamic fuzzy controller proposed in this paper is used to find the optimal control force required for active nonlinear control of building structures. This method has achieved successful results in closed system design from the example.

• Analytical Science and Technology
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• v.6 no.4
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• pp.369-374
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• 1993

Plasma oscillation has been observed during the development of the glow discharge as detector for gas chromatography. The variation of oscillation frequency shows the better stability and detection limits than the changes in the dischange curent. To investigate the range of useful operating conditions and to gain insight into the mechanism, the effect of experimental parameters on plasma oscillation have been studied. This study includes the variation of discharge current, pressure and discharge gap. Frequency ranges of 10KHz to 10MHz have been observed with the various shapes of oscillation. Two kinds of mode for oscillation are observed with the variation of electrode gap at low pressure and low voltage.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.701-707
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• 2006

Disinfectant residual should be maintained to achieve biological stability during distribution of treated water. The wide distribution of retention times associated with storage and transport of water in a network and the reactivity of disinfectants make it difficult to maintain adequate residuals at critical locations. Rechlorination at some intermediate locations may reduce the total disinfectant dose while keeping residuals within specified limits throughout the water distribution system. In order to select the adequate location of rechlorination for achieving to maintain of residual chlorine throughout the distribution system, EPANET was used in this study. EPANET was well predicted chlorine transport and residual loss in the distribution system. Location of rechlorination was selected to maintain 0.4mg/L of residual chlorine throughout a water distribution system by field investigation and model simulation. The quantity of chlorine may reduced 36.7% and provided smooth residual between 0.42 and 0.60mg/L, when rechlorination would be used continuously at strategic location within the distribution system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.133-140
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• 2002

This article presents an application of a large-scale structural mixing model(Broadwell et at. 1984) to the blowout of turbulent reacting cross flow jets. Experimental observations, therefore, aim to identify the existence of large-scale vortical structure exerting an important effect upon the flame stabilization. In the analysis of common stability curve, it is seen that the phenomenon of blowout are only related to the mixing time scale of the two flows. The most notable observation is that the blowout distance is traced at a fixed positions according to the velocity ratio at all times. Measurements of the lower blowout limits in the liftable flame are qualitatively in agreement with the blowout parameter $\xi$, proposed by Broadwell et al. Good agrement between the results calculated by a modified blowout parameter $\xi$'and the present experimental results confirms the important effect of large-scale structure in the stabilization feature of blowout.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.3
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• pp.181-188
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• 2019

Purpose: This study was performed to determine the effects of a gluteus maximus strengthening exercise on both spinal alignment and dynamic balance in subjects with kyphosis. Methods: We measured the kyphosis angle of 150 subjects and selected those whose kyphosis angle was > $50^{\circ}$. The participants included 10 male and 12 female college students. After a gluteus maximus strengthening exercise was applied, the subjects were measured by the formetric 4D and Biorescue systems. The collected data were analyzed by a paired t-test with the SPSS (Ver. 21) program for spinal alignment and dynamic balance comparisons both before and after the gluteus maximus strengthening exercise was completed. Results: The results regarding spinal alignment showed statistically significant decreases in pelvic tilt, kyphotic angle, and lordotic angle after the intervention (p < .05). However, trunk imbalance, pelvic torsion, surface rotation, and lateral deviation were not significantly different after the exercise. The results of the dynamic balance showed statistically significant increases in limits of stability after the exercise (p < .05). Conclusion: The above results suggest that the implemented gluteus maximus strengthening exercise may be effective for spinal alignment and dynamic balance in subjects with kyphosis.