• Restorative Dentistry and Endodontics
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• v.47 no.2
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• pp.17.1-17.8
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• 2022

Endodontic microsurgery is a predictable treatment option when orthograde treatment or retreatment is unsuccessful or unfeasible. However, when there is a gross compromise of periapical bone, achievement of bone regeneration after the surgical procedure may be hampered. In such cases, the application of guided tissue regeneration principles, with adjunctive use of leukocyte platelet-rich fibrin to fill the bone defect as a bone substitute and as a membrane to cover the site, provides a cost-effective solution with the benefits of accelerated physiological healing and reduced post-surgical pain and discomfort. This case report presents 2 cases of endodontic microsurgery of the upper lateral incisors with loss of buccal cortical plate, where platelet-rich fibrin was successfully applied.

• Journal of Korea Foundry Society
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• v.20 no.5
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• pp.307-315
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• 2000

The effects of additional elements on the mechanical properties of HSLA cast steels such as hardness, tensile strength and charily impact energy have been investigated. Test results showed the mechanical properties of HSLA cast steels were superior to those of C-Mn cast steels. In case of the HSLA cast steels, HSLA cast steels with all addition of Nb, V, and Ti had more excellent tensile strength than those with individual addition of Nb, V, or Ti. The tensile strengths of HSLA cast steels were increased as the Mo contents were increased from 0.25% to 0.5%. These are attributed to the solution hardening and the change of the precipitation kinetics of NbC due to increased Mo contents. The tensile strength of HSLA cast steel was remarkablely increased as the manganese contents were increased from 0.65% to 1.2% and 1.5%, respectively. However, the optimum composition of HSLA cast steels to obtain the best compromise between tensile strength and charily impact energy compared to C-Mn cast steel was the additions of0.1% C and 1.2% Mn.

• The Journal of Fisheries Business Administration
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• v.45 no.3
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• pp.111-129
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• 2014

The main purpose of this study is to analyze the disputes concerning the 1982 moratorium on commercial whaling and the standing rights of other natural objects. Basically, the debates has arisen from the very nature of whales and other natural resources, that is to say, a mixed good of consumptive and non-use value. The debates between pro- and anti-moratorium states regarding whaling may not find out a peaceful solution without compromise or negotiation since any international institution for official settlements does not exist. If the pro-states could provide anti-states with a certain type of economic incentive which is side payments, anti-states might offer self-restraint not to whale. Here, it would be considered to apply Kaldor-Hicks compensation principles to this problem. Since 1965, some countries such as the United States and Japan began to recognize the standing right of natural objects. Even though rejected, the newt case in Korea was brought to the Supreme Court. If a standard of living increases significantly to a higher level(i.e. more than per capita income US$30,000), there would be a tendency of valuing natural objects and their beauty more and more highly.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.2
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• pp.254-261
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• 1999

An optimal design code for centrifugal pumps has been developed to determine geometric and fluid dynamic variables under appropriate design constraints. The optimization problem has been formulated with a nonlinear objective function to minimize one, two or all of the fluid dynamic losses, the net positive suction head required and the product price of a pump stage depending on the weighting factors selected as the design compromise. The optimal solution Is obtained by means of the Hooke and Jeeves direct search method. The performance analysis Is based on the mean streamline analysis using the present state-of-the-art loss correlations. The optimized efficiency and design variables of centrifugal pumps are presented in this paper as a function of non-dimensional specific speed in the range, $0.5{\leq}N$, ${\leq}1.3$. The diagrams presented herein can be used efficiently in the preliminary design phase of centrifugal pumps.

• Korea Journal of Hospital Management
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• v.21 no.3
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• pp.65-70
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• 2016

The Long-Term Care Hospital (LTCH) accreditation system was initiated in 2013 in the form of mandatory accreditation system in order to improve patient safety and the quality of medical service at LTCHs. By June 2016, the accredited LTCHs were 76.2%. This research was conducted to review the implementation process in the first cycle and to promote development of the second cycle of LTCH accreditation system. There are some changes which reinforced the accreditation standards, accreditation survey, and public access to accreditation results in order to strengthen patient safety in the first cycle LTCH accreditation system. LTCHs which participated in the accreditation system achieved certain outcomes in respect to patient safety and employee satisfaction. However, there are several urgent problems in placement criteria of night duty health care providers, reinforcement plans in the accreditation system, and incentives for accredited hospitals. In order to solve these problems, the most important thing is to clearly recognize the fact that the healthcare accreditation system is not the means for control and regulate hospitals but a system to induce hospitals to continue to strive for improvements in patient safety and medical service quality. In addition, it is required that LTCHs, accrediting agency and the Ministry of Health and Welfare compromise and cooperate to seek solutions every time issues related to the accreditation system arise.

• Steel and Composite Structures
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• v.21 no.3
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• pp.605-628
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• 2016

The energy absorption characteristics of diamond core sandwich cylindrical columns under axial crushing process depend greatly on the amount of material which participates in the plastic deformation. Both the single-objective and multi-objective optimizations are performed for columns under axial crushing load with core thickness and helix pitch of the honeycomb core as design variables. Models are optimized by multi-objective particle swarm optimization (MOPSO) algorithm to achieve maximum specific energy absorption (SEA) capacity and minimum peak crushing force (PCF). Results show that optimization improves the energy absorption characteristics with constrained and unconstrained peak crashing load. Also, it is concluded that the aluminum tube has a better energy absorption capability rather than steel tube at a certain peak crushing force. The results justify that the interaction effects between the honeycomb and column walls greatly improve the energy absorption efficiency. A ranking technique for order preference (TOPSIS) is then used to sort the non-dominated solutions by the preference of decision makers. That is, a multi-criteria decision which consists of MOPSO and TOPSIS is presented to find out a compromise solution for decision makers. Furthermore, local and global sensitivity analyses are performed to assess the effect of design variable values on the SEA and PCF functions in design domain. Based on the sensitivity analysis results, it is concluded that for both models, the helix pitch of the honeycomb core has greater effect on the sensitivity of SEA, while, the core thickness has greater effect on the sensitivity of PCF.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.257-263
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• 2011

Sparse-view CT imaging is considered to be a solution to reduce x-ray dose of CT. Sparse-view CT imaging may have severe streak artifacts that could compromise the image qualities. We have compared quality of sparseview images reconstructed with two representative iterative reconstruction techniques, SIRT and TV-minimization, in terms of image error and edge preservation. In the comparison study, we have used the Shepp-Logan phantom image and real CT images obtained with a micro-CT. In both phantom image and real CT image tests, TV-minimization technique shows the best performance in error reduction and preserving edges. However, the excessive computation time of TV-minimization is a technical challenge for the practical use.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.199-207
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• 2008

Many logistics enterprises have made efforts to achieve low costly and high efficient logistics network. The cross-docking system can be a good solution for them. However, it requires tight schedule and all-night operation inevitably for realization of ideal cross-docking. These causes the difficulty of the attainment of daily delivery target and the leave of delivery service persons. In this paper, we develop the line-haul and shuttle service compromised cross-docking model in order to solve the problems practically. We apply the storage process with the cross-docking system and the direct cross-docking between line-haul and shuttle services. The simulation model validates the shorter delivery time by the developed model than the present model.

• ETRI Journal
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• v.38 no.6
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• pp.1240-1249
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• 2016

With the number of IP cores in a multicore system-on-chip increasing to up to tens or hundreds, the role of on-chip interconnection networks is vital. We propose a networks-on-chip-style bus network as a compromise and redefine the exploration problem to find the best IP tiling patterns and communication path combinations. Before solving the problem, we estimate the time complexity and validate the infeasibility of the solution. To reduce the time complexity, we propose two fast exploration algorithms and develop a program to implement these algorithms. The program is executed for several experiments, and the exploration time is reduced to approximately 1/22 and 7/1,200 at the first and second steps of the exploration process, respectively. However, as a trade-off for the time saving, the time cost (TC) of the searched architecture is increased to up to 4.7% and 11.2%, respectively, at each step compared with that of the architecture obtained through full-case exploration. The reduction ratio can be decreased to 1/4,000 by simultaneously applying both the algorithms even though the resulting TC is increased to up to 13.1% when compared with that obtained through full-case exploration.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1231-1236
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• 2004

In the present work, the practical thermal design process of 1 DIN car DVD receiver described. In the course of its efficient design, CAE technique was essentially used. CAE technique has reduced research period, man power and material cost but has increased research convenience, organized results and persuasive power. CAE technique helped to study parameters such as vent, fan and heat sink. Using these elements, it tried to meet optimal thermal solution. But safety standard, printed circuit board and framework mechanism should be considered as the constraint. To overcome these constraints, we tried to communicate and compromise with projectors in charge. After all, the price of those efforts has made the most competitive heat sink for heat dissipation in the 1 DIN car DVD receiver market. Moreover, we are trying to save $3 per product by removing fan. This paper is supposed to show an example of the CAE technique and help thermal designers to make electronic packaging goods.