• International Area Studies Review
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• v.18 no.3
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• pp.231-248
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• 2014

The relationship between market structure and social welfare outcomes has received considerable critical attention in the field of competition policy research. In particular, it is necessary to study in greater depth the impact of market power on social welfare in the telecommunications industry, which is highly likely to form a monopolistic market structure. This is because, when market powers are concentrated on few upper carriers, there are negative effects on social welfare due to an excess of profits. Against this background, the present study investigates the relationship between the market structure of the mobile communications industry (the level of market power) and social welfare outcomes (the retail rate cut) through an international comparison. The results demonstrate that both the market structure and competition status of the Korean market have had significant gaps in global trends. It also points out that the monopolistic market structure (when the leading provider has more than 50% of the market share) has significantly negative effects on consumer welfare (the retail price cut). In addition, the findings of this study suggest that the direction of competition policy should focus on not only improving market concentration(HHI), but also on mitigating the monopoly of power of a dominant operator.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.799-801
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• 2002

To develop GIS (Gas Insulated Switchgear), prediction of the flow field including pressure in GIS is very important. The transport phenomena in GIS including arc is also being studied in these days. In this study, to predict the arc behaviour for GIS with voltage rating up to 800kV developed by HHI (Hyundai Heavy Industries Co. Ltd.), the analysis of flow and electric field in GIS were investigated. To simulate the compressible flow in GIS, the CFX, commercial CFD code, was used. The movement of the piston and the electrode of the GIS was simulated with moving grid method, which was superior to the method of varying the property of cells in the aspect of accuracy and convergence of solution. The calculated maximum pressure within the puffer cylinder was matched with experimental data within 5% error. Also, the oscillation of pressure in GIS after the movement of electrode was well predicted.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.185-189
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• 2012

Objective: The aim of this paper is to introduces Hyundai Heavy Industry's ergonomic risk assessment tool, H-OWAS, which is considering work load and frequency compared to the OWAS. Background: As prevalence of work-related musculoskeletal disorders(WMSDs) in ship building industries has been much higher than that in other industries, most of the large scaled corporations have implemented their own prevention program since legislation on the prevention of WMSDs had introduced in 2003. Method: This paper introduces WMSDs prevention program, HEMP(HHI Ergonomics Management Program) which consists of risk assessment, improvement efforts of working environments, medical treatment and training/evaluation and describes how to operate the program. We also describe application of OWAS method considering work load and frequency for risk factor analysis(H-OWAS) and shows methodology for assessing the ergonomic risk factor. And comparison of the assessment results between OWAS and H-OWAS is carried out by statistical analysis. Result: There was statistically significant difference in the assessment results between OWAS and H-OWAS, and regression shows H-OWAS explains the borg's scale of perceived exertion more clearly than OWAS. Conclusion: H-OWAS has been proved more effective tool than OWAS to evaluate ergonomic risk factor under real working condition. Application: H-OWAS can be widely applied to the many other companies when implementing the ergonomics risk assessment.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.3
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• pp.141-147
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• 2018

Purpose : Aim of the this study was conducted to determine whether hearing aids are responsible for the quality of life by comparing quality of life between the elderly who are suspected of difficulty in hearing selected by Hearing Handicap Inventory of Elderly (HHIE) without using hearing aids and who are using hearing aids. Methods : For the study, two groups of 33 people were analyzed for independent t-test based on whether they wore Hearing Aids (HA) or not whom wearing hearing aids (hearing aids users) and suspected difficulty in hearing. who are attending the Religious organization Senior Welfare Center in the OO region. Result : The quality of life of hearing aid users is generally observed to be higher than that of non-users in general, and by the section, psychological (p=0.019) and living environment (p=0.032) were appeared statistically signigicant. The elderly showed a significant difference. In the section, "Operation Satisfaction (p=0.038)" in the physical health area, "relationship of reason (p=0.018)" in the social relationship area, "Economic margin (p=0.021)" in the environmental area, "Information accessibility (p=0.020)", In the psychological area, hearing aid was used for "self satisfaction (p=0.033)", "concentration of work (p=0.045)". Conclusion : The use of hearing aids by hearing loss elderly improves the quality of life in the psychological health and living environment section.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.864-870
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• 2005

Hydraulic excavators have been popular devices in construction field because of its multi-workings and economic efficiency. The mathematical models of excavators have many nonlinearities because of nonlinear opening characteristics and dead zone of main control valve, oil temperature variation, etc. The objective of this paper is to develop a simulator for hydraulic excavator using AMESim. Components and whole circuit are expressed graphically. Parameters and nonlinear characteristics are inputted in text style. From the simulation results, fixed spring stiffness of MCV can't satisfy accuracy of spool displacement under whole P-Q diagrams. Closed loop type MCV containing proportional gain is proposed in this paper that can reduce displacement error. The ability of closed loop MCV is verified through comparing with normal type MCV using AMESim simulator. The simulator can be used to forecastexcavator behavior when new components, new mechanical attachments, hydraulic circuit changes, and new control algorithm are applied. The simulator could be a kind of development platform for various new excavators.

• Journal of Navigation and Port Research
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• v.34 no.7
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• pp.567-575
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• 2010

Ningbo Port develops quickly in recent years and with the combination of Ningbo Port and Zhoushan Port, it becomes another important port in the Shanghai International Shipping center. Competition between the two biggest ports in this area can't be avoided. The goal of this paper is investigating the competence of port from two angles, which are spatial structure of the ports cluster and neighboring ports' attraction to cargoes at conjunct hinterlands. The paper firstly uses the HHI index model and shift-share method to qualitatively and quantitatively analyze the data of container throughputs of ports in the shipping center, in order that investigates the spatial structure of ports cluster. Basing on above researches, the paper employs the location quotient to study Shanghai port and Ningbo port's hinterland distributions at Zhejiang province. The conclusion of this study:(I)the ports cluster of the Shanghai International Shipping Center is highly centralized, and undergoes a porcess of first centralization then decentralization since the mid of 90s, last century. (2)Hinterlands of Shanghai port includes: Hangzhou, Jiaxing, Huzhou and Quzhou districts; Hinterlands of Ningbo port includes: Ningbo, Taizhou and Zhoushan districts.

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.38-45
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• 2017

FPSO is widely used to develop deep sea oil fields and HHI has constructed ten(10) FPSOs. During these constructions, relevant structural design criteria such as yielding, buckling, fatigue, collision and impact strength were applied to verify structural safety. To apply the buckling strength evaluation for structures, the critical buckling stresses and applied stresses of relevant panels should be calculated. The plate and stiffened panels are to be idealized, which are needed much time and efforts by designers. Therefore, program development is necessary in order to evaluate the buckling strength conveniently and accurately. In this study, the buckling strength assessment system by using offshore code, DNV-RP-C201 was developed under MSC/PATRAN, pre-post program of finite element method. Graphic user interface program is written in MSC/PATRAN PCL functions. Source program to evaluate the buckling strength is developed in FORTRAN programming languages. The developed program is verified by comparing with the results of the Nauticus Hull developed by DNV Classification Society, and applied to the marine construction project conducted by Hyundai Heavy Industries LTD.

• ETRI Journal
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• v.31 no.1
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• pp.21-30
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• 2009

In low bit-rate video transmission, the payload of a single packet can often contain a whole coded frame due to the high compression ratio in both spatial and temporal domains of most modern video coders. Thus, the loss of a single packet not only causes the loss of a whole frame, but also produces error propagation into subsequent frames. In this paper, we propose a novel whole frame error concealment algorithm which reconstructs the first of the subsequent frames instead of the current lost frame to suppress the effects of error propagation. In the proposed algorithm, we impose a constraint which uses side match distortion (SMD) and overlapped region difference (ORD) to estimate motion vectors between the target reconstructed frame and its reference frame. SMD measures the spatial smoothness connection between a block and its neighboring blocks. ORD is defined as the difference between the correlated pixels which are predicted from one reference pixel. Experimental results show that the proposed algorithm effectively suppresses error propagation and significantly outperforms other conventional techniques in terms of both peak signal-to-noise ratio performance and subjective visual quality.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.806-811
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• 2001

Since the characteristics of combustion and pollutant in Diesel engines were mainly effected by the characteristics of in-cylinder gas flow and fuel spray, an understanding of those was essential to the design of the D.I. Diesel engines. The improvement of volumetric efficiency of air charging into combustion chamber is a primary requirement to obtain better mean effective pressure of an engine. Since parameters such as the air resistances in intake and exhaust flow passages, valve lift and valve shape influence greatly to the volumetric efficiency, it is very important to investigate the flow characteristics of intake and exhaust port which develops air motion in the combustion chamber. In this study, two approach methods were used for design intake and exhaust port; experiment and computation which were made by using steady flow test rig and commercial CFD code. This paper presents the results of an experimental and analytical investigation of steady flow through the prototype cylinder head ports and valves of the HHI's H21/32 HIMSEN Engine.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.133-143
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• 2020

The paper investigates the factors affecting the profitability of commercial banks in Asian developing countries, including Vietnam, Malaysia and Thailand. We use panel data of four entities; ten banks in Vietnam, eight banks in Malaysia, nine banks in Thailand and all 27 commercial banks from the period 2012 to 2016. Particularly, Return on Asset, Return on Equity and TOBINQ are defined as profitability indicators, which are impacted by three main types of independent variables, namely bank-specifics, which include CAR, NPL, Cost to income, Liquidity ratio and Bank size, industry-specific variable-concentration HHI and macroeconomic-specific variables, which consist of GDP growth and Inflation. Using panel data regressions, the paper identifies several similarities and differences among empirical results on the models of four entities, each of three countries and the overall sample. The most outstanding similarity is that all entities record the significantly negative relationship between operational risk and banking profitability. Likewise, the significantly negative influence of bank size to profitability is found on models of Vietnam and Thailand and no significant effect on the model of Malaysia. Meanwhile, the most controversial result comes up with the negative relationship between CAR and profitability indicators as well as the positive association between credit risk and banking profitability.