• Structural Engineering and Mechanics
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• v.53 no.6
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• pp.1167-1182
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• 2015

In this study, the stresses and electric potential redistributions of a cylinder made from functionally graded piezoelectric material (FGPM) are investigated. All the mechanical, thermal and piezoelectric properties are modeled as power-law distribution of volume fraction. Using the coupled electro-thermo-mechanical relations, strain-displacement relations, Maxwell and equilibrium equations are obtained including the time dependent creep strains. Creep strains are time, temperature and stress dependent, the closed form solution cannot be found for this constitutive differential equation. A semi-analytical method in conjunction with the Mendelson method of successive approximation is therefore proposed for this analysis. Similar to the radial stress histories, electric potentials increase with time, because the latter is induced by the former during creep deformation of the cylinder, justifying industrial application of such a material as efficient actuators and sensors.

• Journal of Industrial Technology
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• v.18
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• pp.241-248
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• 1998

In this study, a modeling method of power-assisted steering systems and driver models for vehicle dynamic analysis using AUTODYN7 is presented. Pressure-flow relations of flow control valve are derived, and the equations of motion of a steering gear are obtained. Combining pressure-flow relations and equations of motion, the steering force can be represented as a function of steering wheel angle or torque. Driver model was modeled based on a PID controller and forward target method. With the steering systems and driver model, various driving tests are conducted using AUTODYN7.

• Journal of Families and Better Life
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• v.11 no.1
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• pp.203-217
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• 1993

The purpose of this study was to investigate relations of decision-making power of the elderly to home management and life satisfaction by applying a social behavior theory and exchange theory and to find out the device which improve the elderly life satisfaction at the home management view. For these research tasks the data was collected through the questionaire and interview those respondents were 273 woman elderly living with one of their married children in Seoul. It was analyzed by various statistical methods such as Frequency Percentile ANOVA F-test t-test Pearson's Corrdlation Analysis Multiple Regression Analysis. The results of this study are as follows: 1) Decision-making power of the elderly to home management had significant differences according to all of th variables except for religion job status of the elderly and education income of the children. 2) Decision-making power of the elderly to home management had the significant differences according to the variable such as income of the elderly solidarity between the elderly and their adult children age of the elderly The most influencial factor was income of the elderly. 3) Elderly life satisfaction had significant differenced according to all of the variables except for age job status of the elderly and education income of the children inmate children 4) In the result of analyzing the elderly life satisfaction the most influencial factor was decision-making power to home management and the explanary power to home management and the explanary power of those variables for the elderly life satisfaction was 56.2%.

• Journal of Contemporary Eastern Asia
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• v.17 no.1
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• pp.5-26
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• 2018

Joseph S. Nye defined soft power as the power of attraction to affect the behavior of other states through the use of non-coercive instruments including culture, political values and foreign policy. Over the last two decades, environmental issues have grown in importance on the international agenda and become critical components of states' foreign policy-making. This paper aims to analyze environmental foreign policy as a soft power instrument focusing on two major rising powers: China and India. Traditionally, China and India had been reluctant to make any commitments in the field. However, they have shown greater willingness to act in global environmental governance in the past decade. They started playing more active roles in global climate change negotiations and supported a number of initiatives. Their current rise in global environmental governance has even been praised by the international community as the Paris agreement case demonstrated. This study evaluates China's and India's recent efforts in global environmental governance with a focus on climate change negotiations linking their constructive position to their soft power potential. It is argued that environmental issues are used by these two states as foreign policy strategy to gain more influence in international politics. This study finds out that China's climate-related environmental diplomacy has been more ambitious than that of India and thus has been closer to fulfill its potential as a soft power asset.

• Strategy21
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• s.36
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• pp.180-214
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• 2015

The Republic of Korea navy challenged from the unexpected surprise attacks by the North Korea navy, albeit, the developments of up-to-date naval forces' technology, and the ceaseless efforts for war preparedness. My study divided into two categories. Qualitative methods used for literature review of international relations theory related to the war onset and for investigating events occurred on the Peninsula and its surrounding seas from 1968 to 2007. Quantitative method used such as the analyses of national power index of the two Koreas, the United States, and China, the uses of equation model to calculate power index of alliance, COPDAB(Conflict and Peace Data Bank) index analysis. Like Choi's study on East Asia maritime conflict, as a conclusion, considering both AT theory and maritime national power as a tool for predicting maritime conflict in the Peninsula proved significant. Based on the study, ROK navy need to prepare for the maritime conflict because the results showed North Korea would initiate maritime disputes sooner or later using fatal asymmetric forces and methods. As a policy suggestion, we are required to maintain a concrete ROK-US alliance ties and to construct naval forces due to the deterring functions of maritime national power.

• Strategy21
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• s.36
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• pp.5-32
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• 2015

Geopolitics or Political Geography is an essential academic field that should be studied carefully for a more comprehensive analysis of international security relations. However, because of its tarnished image as an ideology that supported the NAZI German expansion and aggression, geopolitics has not been regarded as a pure academic field and was rejected and expelled from the academic communities starting from the Cold War years in 1945. During the Cold War, ideology, rather than geography, was considered more important in conducting and analyzing international relations. However, after the end of the Cold War and with the beginning of a new era in which territorial and religious confrontations are taking place among nations - including sub national tribal political organizations such as the Al Quaeda and other terrorist organizations - geopolitical analysis again is in vogue among the scholars and analysts on international security affairs. Most of the conflicts in international relations that is occurring now in the post-Cold War years can be explained more effectively with geopolitical concepts. The post - Cold War international relations among East Asian countries are especially better explained with geopolitical concepts. Unlike Europe, where peaceful development took place after the Cold War, China, Japan, Korea, the United States, Taiwan and Vietnam are feeling more insecure in the post-Cold War years. Most of the East Asian nations' economies have burgeoned during the Cold War years under the protection of the international security structure provided by the two superpowers. However, after the Cold War years, the international security structure has not been stable in East Asia and thus most of the East Asian nations began to build up stronger military forces of their own. Because most of the East Asian nations' national security and economy depend on the oceans, these nations desire to obtain more powerful navies and try to occupy islands, islets, or even rocks that may seem like a strategic asset for their economy and security. In this regard, the western Pacific Ocean is becoming a place of confrontation among the East Asian nations. As Robert Kaplan, an eminent international analyst, mentioned, East Asia is a Seascape while Europe is a Landscape. The possibility of international conflict on the waters of East Asia is higher than in any other period in East Asia's international history.

• Strategy21
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• s.38
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• pp.47-82
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• 2015

To control the sphere, it required a strategic understanding to sphere and a power for overcome to it. In the early 20th century, the Pacific-War is a confrontation between the U.S. and the Japan for holding supremacy a pacific ocean sphere, building on maritime geopolitical perception. The Pacific ocean is a large of sphere, so if a country pursues a Pacific region supremacy, it needs a strategic perception and capability to control the sphere. After the U.S. has unified the continental, it has formed geopolitical perception in the Pacific ocean and by the way to control the Pacific ocean selected a naval power. The U.S. must have overcome a Pacific sphere for getting through to the Pacific region, this concept has developed the War Plan Orange(war plan relations with the Japan). Meanwhile, at this point of time, the Japan has recognized to a geopolitical point of view about security environment in the Pacific ocean. like as the U.S. has the War Plan Orange in mind for building on geopolitical perception of the Pacific ocean, the Japan also has learned geopolitical perception from the U.S. Because of this, the Japan has established the Interception-Attrition strategy(war plan relations with the U.S.). If we don't have overcome a sphere of the Pacific ocean, we don't hold hegemony of the Asia-Pacific region. So the analysis of perspective maritime geopolitics about the Pacific war is a meaningful study.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.51-56
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• 2002

High pressure hose having tuning cables, called 'Resonator hose' is frequently used to attenuate pressure ripple generated by the pump for reducing the vehicle interior noise. A number of studies have been conducted on the resonator hose and its analytical models. However, there are few studies which deal with the influence of resonator hose on vehicle interior noise because the most of studies focused on transmission loss of the resonator hose. This paper presents NVH test results of power steering system and frequency analysis results. In the frequency analysis, both the relations between vibration, pressure ripple and vehicle interior noise and also the design parameters of high pressure hose influencing on vehicle interior noise were discussed. The test was done for various high pressure hose specimens in full turn condition.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.13 no.1
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• pp.55-72
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• 2009

A misclassified size-biased modified power series distribution (MSBMPSD) where some of the observations corresponding to x = c + 1 are misclassified as x = c with probability $\alpha$, is defined. We obtain its recurrence relations among the raw moments, the central moments and the factorial moments. Discussion of the effect of the misclassification on the variance is considered. To illustrate the situation under consideration some of its particular cases like the size-biased generalized negative binomial (SBGNB), the size-biased generalized Poisson (SBGP) and sizebiased Borel distributions are included. Finally, an example is presented for the size-biased generalized Poisson distribution to illustrate the results.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.10
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• pp.45-52
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• 1997

An analysis method for the electromagnetic scattering of a gaussian beam wave by finite periodic conducting strip grating on a groudned dielectric slab is considered. The intergral equation for the unknown current induced on the conducting strip surface is derived and solbed numerically by use of the method of moment. From knowledge of the strip current, the quantities of interest such as radiation pattern, the space wave power radiated into the free space, and the coupled surface wave power propagating along the dielectric slab are computed for the appropriately chosen parametes Some similarity between scattering behaviours of the present geometry and the infinite geometry is examined by observing the Off-bragg as well as bragg blaxing penomena in both geometries.The validity of the numerical results are assured by a check of the power conservation relations.