• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.687-697
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• 2004

This paper is aimed to guide ocean-going companies to reasonable decisions and to increase the competitiveness of Korean shipping industry by clarifying the determinants of political costs of ocean-going companies, which only depend for the enormous amount of money to introduce the operating fixed assets, or the vessels, upon the supporting policy from the government or the loan from the related financial institutions. As independent variables of the political costs, 5 elements were settled such as company size(sales, total assets and market share), debit ratio, capital concentration ratio, profitability(operating profit) and marine risk(sales fluctuation). To verify the relations and the effect level between dependent variables and political costs, the Multiple Regression Analysis Model was applied The result of the analysis shows significantly positive relations between size variables and political cost of shipping industry. Moreover, debt ratio and profitability were proved significant related with political costs of shipping industry.

• Journal of Navigation and Port Research
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• v.42 no.2
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• pp.127-136
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• 2018

The motion response of floating structures is of significant concern in marine engineering. Floating structures can be disturbed by waves, winds, and currents that create undesirable motions of the vessel, therefore causing challenges to its operation. For a floating structure, mooring lines are provided in order to maintain its position; these should also produce a restoring force when the vessel is displaced. Therefore, it is important to investigate the tension of mooring lines and the motion responses of a twin barge when moored to guarantee the safety of the barge during its operation. It is essential to precisely identify the characteristics of the motion responses of a moored barge under different loading conditions. In this study, the motion responses of a moored twin barge were measured in regular waves of seven different wave directions. The experiment was performed with regular waves with different wavelengths and wave directions in order to estimate the twin-barge motions and the tension of the mooring line. In addition, the motion components of roll, pitch, and heave are completely free. In contrast, the surge, sway, and yaw components are fixed. In the succeeding step, a time-domain analysis is carried out in order to obtain the responses of the structure when moored. As a result, the Response Amplitude Operator (RAO) motion value was estimated for different wave directions. The results of the experiment show that the motion components of the twin barge have a significant effect on the tension of the mooring lines.

• Earthquakes and Structures
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• v.9 no.3
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• pp.603-623
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• 2015

The scale and nature of the recent earthquakes in the world and the related earthquake disaster index coerce the concerned community to become anxious about it. Therefore, it is crucial that seismic lateral load effect will be appropriately considered in structural design. Application of seismic isolation system stands as a consistent alternative against this hazard. The objective of the study is to evaluate the structural and economic feasibility of reinforced concrete (RC) buildings with base isolation located in medium risk seismic region. Linear and nonlinear dynamic analyses as well as linear static analysis under site-specific bi-directional seismic excitation have been carried out for both fixed based (FB) and base isolated (BI) buildings in the present study. The superstructure and base of buildings are modeled in a 3D finite element model by consistent mass approach having six degrees of freedom at each node. The floor slabs are simulated as rigid diaphragms. Lead rubber bearing (LRB) and High damping rubber bearing (HDRB) are used as isolation device. Change of structural behaviors and savings in construction costing are evaluated. The study shows that for low to medium rise buildings, isolators can reduce muscular amount of base shears, base moments and floor accelerations for building at soft to medium stiff soil. Allowable higher horizontal displacement induces structural flexibility. Though incorporating isolator increases the outlay, overall structural cost may be reduced. The application of base isolation system confirms a potential to be used as a viable solution in economic building design.

• Journal of Convergence for Information Technology
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• v.10 no.1
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• pp.1-12
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• 2020

The Government provides a financial assistance to stimulate firm R&D and innovation activities. Previous papers on the impact of public subsidies on firm R&D investments mainly had a focus on an individual policy tool regardless of potential impacts of other policy instruments. This study addresses this gap by examining the effects of policy mix regarding a subsidy and a tax credit. The empirical analyses from fixed effect model using Survey on Technology of SMEs 2015-2017 revealed valuable points. First, policy mix induces more R&D investment of SMEs, which in turn, shows a complementary relationship between two instruments. Second, even if impact of tax credit controlled, subsidy is positively associated with SMEs R&D investment. These findings justify policy mix interventions to promote SME R&D activity. Moreover, grants can be applied as a more useful policy tool for SMEs that are constrained by resources and capabilities.

• Journal of Korean Dental Science
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• v.5 no.1
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• pp.13-20
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• 2012

Purpose: The purpose of this study was to investigate the effect of patterning on the stress distribution in the bone tissue using the finite element analysis (FEA) model. Materials and Methods: For optimal comparison, it was assumed that the implant was axisymmetric and infinitely long. The implant was assumed to be completely embedded in the infinitely long cortical bone and to have 100% bone apposition. The implant-bone interface had completely fixed boundary conditions and received an infinitely big axial load. von Mises stress and maximal principal stress were analyzed. Conventional thread and 2 or 3 patterns on the upper and lower flank of the thread were compared. Result: The surface areas of patterned implants were increased up to 106~115%. The thread with patterns distributed stress better than conventional thread. Patterning in threads may produce more stress in the implant itself, but reduce stress in the surrounding bone. Stress patterns of von Mises stress were favorable with patterns, while the maximal principal stress was increased with patterns. Patterns in the lower flank showed favorable stress distribution. Conclusion: The patterns in implant thread reduce the stress generated in surrounding bone, but the number and position of patterns were crucial factors in stress distribution.

• Structural Engineering and Mechanics
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• v.31 no.4
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• pp.453-475
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• 2009

The literature regarding the free vibration analysis of Bernoulli-Euler and Timoshenko beams on elastic soil is plenty, but the free vibration analysis of Reddy-Bickford beams on elastic soil with/without axial force effect using the Differential Transform Method (DTM) has not been investigated by any of the studies in open literature so far. In this study, the free vibration analysis of axially loaded Reddy-Bickford beam on elastic soil is carried out by using DTM. The model has six degrees of freedom at the two ends, one transverse displacement and two rotations, and the end forces are a shear force and two end moments in this study. The governing differential equations of motion of the rectangular beam in free vibration are derived using Hamilton's principle and considering rotatory inertia. Parameters for the relative stiffness, stiffness ratio and nondimensionalized multiplication factor for the axial compressive force are incorporated into the equations of motion in order to investigate their effects on the natural frequencies. At first, the terms are found directly from the analytical solutions of the differential equations that describe the deformations of the cross-section according to the high-order theory. After the analytical solution, an efficient and easy mathematical technique called DTM is used to solve the governing differential equations of the motion. The calculated natural frequencies of one end fixed and the other end simply supported Reddy-Bickford beam on elastic soil using DTM are tabulated in several tables and figures and are compared with the results of the analytical solution where a very good agreement is observed and the mode shapes are presented in graphs.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.14 no.1
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• pp.1-14
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• 2010

Backgrounds : Bojungikgitang is one of the most common herbal prescriptions in Oriental Medicine, and it is highly recommended prescription for Nogwonsang syndrome. The Author developed Nogwonsang questionnaire for quantitative evaluation. Nogwonsang questionnaire is consisted of causes that induce fatigue, symptoms that directly associated with fatigue, and secondary symptoms that is induced from fatigue. Purposes : This study aims to verify whether the Bojungikgitang Questionnaire has causality and meaningful path structure by path analysis. Methods : 242 patients from 12 OMD clinics participated in this study. The patients executed a question investigation in the object. Factor analysis was conducted for extraction of factor and abridgment of items. Path analysis was conducted to verify path structure. SPSS 15.0 for Windows and AMOS 7.0 were used for statistical analysis. Results : Overwork factor explains fatigue factor. Coefficient is 0.771. Fatigue factor explains digesting and cold factor. Individually coefficient is 0.632 and 0.465. Model fit is $X^2=61.395$(df=51), GFI=0.960, AGFI=0.939, NFI= 0.924, CFI=0.986, RMSEA=0.029. Path structure is proved to be significant. Conclusions : Further research is needed Gold standard of Nogwonsang. Establishment of Gold standard leads and the collection of data and the research which are objective are possible. Connection of the clinical indexes which are objective on the paperweight outside and leads and the development of the diagnosis tool which is fixed quantity is demanded.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.3
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• pp.198-205
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• 2021

In this paper, the effect of trim variation on the required power of 11,000TEU container ship was investigated under conditions considering the actual operation speed and draft. For each draft condition, the effective power (P_E) and delivered power (P_D) trends were investigated with changes in trim and ship speed. At this time, the displacement volume was fixed same as the value of the even trim condition and the both sinkage at the fore and after perpendicular are confirmed. The test ship speeds were determined by considering the operating speed. Both numerical and experimental methods were used to analyze the effects of trim variation. Numerical analysis results were used for evaluating the resistance performance, and the self-propulsion performance was estimated using experimental data obtained from model test.

• Journal of Korean Neurosurgical Society
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• v.62 no.2
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• pp.193-200
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• 2019

Objective : Endovascular treatment (EVT) outcomes for acute M2 segment of middle cerebral artery occlusion remains unclear because most results are obtained from patients with large artery occlusion in the anterior circulation. The objective of this study was to assess procedural outcomes for acute M2 occlusion and compare outcomes according to thrombus location (M1 vs. M2). Methods : A systematic review was performed for online literature published from January 2004 to December 2016. Primary outcome was successful recanalization rate and symptomatic intracranial hemorrhage (S-ICH) after the procedure. A fixed effect model was used if heterogeneity was less than 50%. Results : Eight articles were included. EVT showed successful recanalization rate of 69.1% (95% confidence interval [CI], 54.9-80.4%) and S-ICH rate of 6.1% (95% CI, 4.5-8.3%). The rates of good clinical outcome at 3 months and mortality were 59.4% (95% CI, 49.9-68.2%) and 14.9% (95% CI, 11.4-19.3%), respectively. According to thrombus location (M1 vs. M2), successful recanalization (odds ratio [OR], 1.539; 95% CI, 0.293-8.092; p=0.610) and S-ICH (OR, 1.313; 95% CI, 0.603-2.861; p=0.493) did not differ significantly. Good clinical outcome was more evident in M2 occlusion after EVT than that in M1 occlusion (OR, 1.639; 95% CI, 1.135-2.368; p=0.008). However, mortality did not differ significantly according to thrombus location (OR, 0.788; 95% CI, 0.486-1.276; p=0.332). Conclusion : EVT seems to be technically feasible for acute M2 occlusion. Direct comparative studies between EVT and medical treatment are needed further to find specific beneficiary group after EVT in patient with M2 occlusion.

• Journal of Technology Innovation
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• v.26 no.4
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• pp.1-28
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• 2018

With the growing number of emerging carmakers, automotive parts manufacturers have to penetrate into emerging markets. They can provide large existing carmakers with fully customized parts because of economies scale, but cannot do this for small emerging carmakers due to their small and highly volatile volume order. Once the order by an emerging carmaker is placed, a part manufacturer is exposed to high risks both of decrease in profit margin and high opportunity cost. The platform-based mass customization can be a solution for cost reduction, but the risks of volatility in volume hard to manage. Tackling this issue, we presents a method of optimizing the product portfolio to maximize profits while managing volatility of volume order by emerging carmakers at an affordable level. It is the first robust product portfolio method to keep the scaled deviation of profits at a fixed level under volume order uncertainty. Also, the effect of on the platform-based mass customization on cost is considered. This model can be a building block of conservative market penetration as well as product development strategy while minimizing the financial risks. We conducted an empirical study of a part manufacturer targeting on eighteen automobile manufacturers in North America, Europe and Asia with it powered lift gate.