• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.5
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• pp.403-408
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• 2004

We suggest new attenuator design and formula using quad spiral shaped defected ground structure (DGS). Series resistors and quarter wavelength transmission line that has a role of inverter have been synthesized for attenuator design and novel attenuator structure using quad spiral shaped DGS is fabricated, the measurements show good agreement with theoretical anticipations. The suggested attenuator could remove peak of insertion loss graph through various attenuation method. The various attenuations are obtained by attached pin-diodes, 10-15dB attenuation leveling is realized for validity of suggested design.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.237-244
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• 2019

This paper suggests novel types of joint mechanisms composed of elastic strings and rigid bodies. All of the human hinge joints have the articular capsule and a pair of collateral ligaments. These fibrous tissues make the joint compliant and stable. The proposed mechanism closely imitates the human hinge joint structure by using the concept of tensegrity. The resultant mechanism has several characteristics shown commonly from both the tensegrity structure and the human joint such as compliance, stability, lightweight, and non-contact between rigid bodies. In addition, the role and feature of the human hinge joints vary according to the origins of a pair of collateral ligaments. Likewise, the locations of two strings corresponding to a pair of collateral ligaments produce different function and motion of the proposed mechanism. It would be one of the advantages obtained from the proposed mechanism. How to make a joint mechanism with different features is also suggested in this paper.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.195-201
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• 2018

This study is attempted to demonstrate the structure of the influencing factors on the performance of services of knowledge based service firms. In the model presented, the structure is that service performance in knowledge-based services are affected by the strategic utilization of knowledge resources and service orientation factors of the service organization. And the service performance are also affected in which the systemization of service processes and customer satisfaction play a mediating role. As an analysis result of examining 148 practitioners engaged in the knowledge service industry, it is necessary to increase the satisfaction of external customers in order to improve service performance in a knowledge-based service organizations. This can be achieved by increasing the satisfaction of internal customers. In addition, for this structure to be successful, the service production process to be provided to the customer must be enhanced. The service production process has been found to be an important factor influencing the internal customer satisfaction and service delivery process, especially in the use of knowledge resource, and customer oriented service among service orientation factors.

• Structural Engineering and Mechanics
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• v.45 no.3
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• pp.311-321
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• 2013

In this study, to have a better judgment on the structural performance, the effects of dynamic Soil-Structure Interaction (SSI) on seismic behaviour and lateral structural response of mid-rise moment resisting building frames are studied using Finite Difference Method. Three types of mid-rise structures, including 5, 10, and 15 storey buildings are selected in conjunction with three soil types with the shear wave velocities less than 600m/s, representing soil classes $C_e$, $D_e$ and $E_e$, according to Australian Standard AS 1170.4. The above mentioned frames have been analysed under two different boundary conditions: (i) fixed-base (no soil-structure interaction), and (ii) flexible-base (considering soil-structure interaction). The results of the analyses in terms of structural lateral displacements and drifts for the above mentioned boundary conditions have been compared and discussed. It is concluded that the dynamic soil-structure interaction plays a considerable role in seismic behaviour of mid-rise building frames including substantial increase in the lateral deflections and inter-storey drifts and changing the performance level of the structures from life safe to near collapse or total collapse. Thus, considering soil-structure interaction effects in the seismic design of mid-rise moment resisting building frames, particularly when resting on soft soil deposit, is essential.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.3
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• pp.67-79
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• 2019

This study examines the impact of corporate governance on capital structure decisions based on a large panel of Chinese listed firms. Using the system Generalized Method of Moments (GMM) estimator to control for unobserved heterogeneity, endogeneity, and persistency in capital structure decisions, we document that the ownership structure plays a significant role in determining leverage ratios. More specially, we find that managerial ownership has a positive and significant impact on firms' leverage, consistent with the incentive alignment hypothesis. We also find that managerial ownership only affects the leverage decisions of private firms in the post-2005 split share reform period. State ownership negatively influence leverage decisions implying that SOEs may face fewer restrictions in equity issuance and may receive favourable treatments when applying for seasoned equity ¿nancing, thus use less debt. Furthermore, our results show that while foreign ownership negatively influences leverage decisions, legal person shareholding positively influences firms' leverage decisions only for state controlled firms. We also find that the board structure variables (board size and the proportion of independent directors) do not influence firms' capital structure decisions. Our findings suggest that recent ownership reforms have been successful in terms of providing incentive to managers through managerial shareholdings to take risky financial choices.

• The KIPS Transactions:PartA
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• v.16A no.3
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• pp.153-158
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• 2009

Analysis of 3-dimensional (3D) protein structure plays an important role of structural bioinformatics. The protein structure visualization is the one of the structural bioinformatics and the most fundamental problem. As the number of known protein structure increases rapidly and the study of protein-protein interaction is prevalent, the fast visualization of large scale protein structure becomes essential. The fast protein structure visualization system we proposed is sophisticated and well designed visualization system using geometry instancing technique. Because this system is optimized for recent 3D graphics hardware using geometry instancing technique, its rendering speed is faster than other visualization tools.

• The Journal of Asian Finance, Economics and Business
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• v.3 no.3
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• pp.39-55
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• 2016

The rapid expansion of China's trade surplus since the mid-eighties and picking up until the onset of 2008-09 global financial crisis has been a key development in the world economy. While growing trade surplus of China has been viewed with cynicism borne out of an undervalued Yuan and for having being a member of WTO since 2001, many others argue that China's trade surplus reflect changes in China's economic and trade structure and associated shifts in its role within regional and global production chains. We address this issue by analyzing: (i) China's growing and changing trade structure as well as changing structure of trade surplus with the rest of the world, USA, Europe, Japan and rest of Asia, (ii) China's revealed comparative advantage (RCA) with the rest of the world, and (iii) how China's trade policies resulted into a shift in China's trade structure. We find that, not only China has made significant inroads in the world trade since its admission to WTO, but also there has been a noticeable shift in China's trade structure with specialization in high-end technology industries wherein China's exports aided by a well calibrated FDI policy.

• Korean Journal of Materials Research
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• v.29 no.8
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• pp.477-482
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• 2019

The magnetic properties and electronic structures of the B20 crystal structure MnGe and MnSi were investigated using the density functional theory with local density approximation. The low symmetry of the B20 crystal structure plays a very important role to make electromagnetic characteristics of these materials. The important result of the calculations is that it can be observed the appearance of a pair of gaps in the density of states near the Fermi level in both compounds. These features are results from d-band splitting by the low symmetry of the crystal field from B20 crystal structure. It can be seen that there is half-metallic characteristics from the density of states in both compounds. The calculation shows that the value of magnetic moment of MnGe is 5 times bigger than that of MnSi even though they have same crystal structure. The electronic structures of paramagnetic case have a very narrow indirect gap just above the Fermi level in both compounds. These gaps acquire some significance in establishing the stability of the ferromagnetic states within the local density approximation. Calculation shows that the Mn 3d character dominates the density of states near the Fermi level in both materials.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.813-821
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• 2021

The relationship between capital structure policy and firm value is interesting to study because the concept of capital structure was initiated by Modigliani and Miller who claimed that the company's capital structure is not a factor in its value. They asserted that linking leverage with firm value was irrelevant. Therefore, this study examined the role of growth opportunities as a moderating variable for the relationship between capital structure and firm value. The population of this study is 300 companies from the manufacturing sector that are listed on the Indonesia Stock Exchange (IDX) for the period 2015-2018. To analyze the data, the subgroup moderation method was employed by dividing the data into two parts: companies with high growth opportunities and companies with low growth opportunities. The results revealed that capital structure had a direct positive effect on firm value. Furthermore, the test results of the two regression models of growth opportunities as the moderating variable are very interesting. It was found that for companies with high growth opportunities, the use of debt had a negative effect on firm value, and conversely, the use of debt had a positive effect on firm value for companies with low growth opportunities. The statistical F-test results proved that growth opportunities are a moderating variable for the relationship between capital structure and firm value.

• Composites Research
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• v.36 no.3
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• pp.173-179
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• 2023

The sandwich structure, consisting of a core and a face sheet, is used for lightweight structural application. Generally, cellular structures like honeycomb, foam, and lattice structures are utilized for the core. Among these, lattice structures have several advantages over other types of structures. In other studies, curved lattice structures were reported to have higher mechanical properties than straight structures by converting shear stresses acting on the structure into compressive stresses. Moreover, the addition of vertical struts can have a positive effect on the mechanical properties of the lattice structure. For the purpose, two lattice structures with Circle Arch (CC) and Circular Arch with a vertical column (CC_C) were studied, which were fabricated by using selective laser sintering was conducted. The result showed that CC_C has dramatic performance improvements in specific strength, modulus, and strain energy density compared to CC, confirming that vertical struts played a significant role in the lattice core. Finite element analysis was employed to determine the cause of the stress behavior of CC and CC_C. This study is expected to help design structurally superior lattice cores and sandwich structures.