• Journal of Power System Engineering
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• v.15 no.6
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• pp.27-34
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• 2011

The increasing capabilities of the computers enable us to utilize various numerical schemes for the time-domain simulations concerned with 3-dimensional free-surface wave problems. There are still difficulties to solve such kind of problems, however. That's because long time simulations with large computational domain are needed in time-domain analysis. So, we need faster and more efficient numerical schemes to get the solutions practically for these problems. In this paper, a high-order spectral/boundary-element method is used for the numerical investigation of physics involved in wave-body interaction. This method is one of the most efficient numerical methods by which the nonlinear gravity waves can be simulated and hydrodynamic forces also can be calculated in time-domain. To get the robust study in these topics, various numerical tests are performed and compared with others' works.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.130-135
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• 2000

In this study the vibration behavior of the stiffened double cylinder was experimently analyzed. Due to the complex structure of the double cylinder the outside cylinder frequency responses to the exciting forces applied on various posi-tions were analyzed by using spectrum analyzer in conjunction with an accelerometer and the natural frequencies were obtained. The technique of time-averaged holographic interferometry is applied to study the vibration characteristics of outside cylinder with stiffening T frame. The experimental data showed that the T frame had salient effect of damping on the testing structure at most of resonances. however the experimental results also revealed interesting phenomenon. At some particular frequencies the T frame. The experimental data showed that the T frame had salient effect of damping on the testing structure at most of resonances. However the experimental results also revealed interesting phenomenon. At some particular frequencies the T frame seemed to behave as a transmitter. In addition it has been successfully demon-started that optical method such as holographic interferometry is well suited for the identification of mode shapes. They can give us a whole-field non-contact measurement instead of the point-wise measurement by accelerometer in classical modal testing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.498-498
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• 2001

Seismic qualification of the Main Control Boards for nuclear power plants has been performed with the guideline of AS ME Section III. US NRC Reg. Guide and IEEE 344 code. The analysis model of the Main Control Boards is consist of beam. shell and mass element by using the finite element method. and, at the same time. the excitation forces and other operating loads for each model are encompassed with respect to different loading conditions. As the fundamental frequencies of the structure are found to be less than 33Hz. which is the upper frequency limit of the seismic load, the response spectrum analysis using ANSYS is performed in order to combine the modal stresses within the frequency limit. In order to confirm the structural and functional integrity of the major components, modal analysis theory is adopted to derive the required response spectrum at the component locations. As all the combined stresses obtained from the above procedures are less than allowable stresses and no mechanical or electrical failures are found from the seismic testing, it concludes the Main Control Boards is dynamically qualified for seismic conditions. Although the authors had confirmed the structural and functional integrity of both Main Control Boards and all the component, in this paper only the seismic analysis of the Main Control Board is introduced.

• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.211-215
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• 2018

Ventilator-associated pneumonia (VAP) is a lung infection that develops in patients receiving mechanical ventilation. VAP contributes to about 50% of hospital-acquired pneumonia in ICU settings. One of the recommendation of the Institute of for Healthcare Improvement ventilator bundle is HOB elevation. HOB elevation affects shearing forces and makes higher risk for pressure injury development. Pressure injury (PI) is localized damage to the skin over a bony prominence. PI prevention guidelines recommend that HOB positioning should be lower to reduce risk for PI development which contradicts VAP prevention guidelines for the HOB between 30 and 45 degrees for ICU patients. This presents a care dilemma and tension. The purpose of this study was to perform a secondary data analysis using cumulative electronic health record data in order to determine the association of HOB elevation with VAP and PI in ICU patients. A secondary data analysis was conducted to determine whether HOB elevation is associated with VAP and PI. HOB elevation was not likely to be associated with VAP prevention whereas it was likely to be related to PI development. This is somewhat contrary to popular data and publications. Prospective cohort study is desired to inform us in an evidence-based fashion what actually is optimal HOB elevation for ventilated patients in ICU settings.

• Strategy21
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• s.36
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• pp.94-120
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• 2015

The Asia-Pacific Region has emerged as a arena of geopolitical competition between the U.S. and China. The Obama administration of the U.S. had laid out the concept of rebalancing strategy toward the region, concentrating its 60 percent of Naval Forces to the region till 2020 and consolidating its network of allies and partners. Whereas Chinese leader Xi Jinping also put forward the concept of new type of major power relations concerning its relations with the U.S. and a concept of 'the Asian Community of Common Destiny' aiming at a more intensified mutual relation among countries in the region. In doing so, Asia-Pacific region gradually became the arena where mutual competition and cooperation between the U.S. and China has crossfired. As a close ally to the U.S. and a partner to Japan, South Korea should develop trilateral naval cooperation by holding joint naval drill with the aim of humanitarian support and disaster relief. At the same time, Seoul also should make efforts to proceed mutual confidence building with Beijing by deepening military-to-military cooperation. These policy options will be helpful to enhance Seoul's security posture in the region.

• Journal of Power System Engineering
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• v.11 no.4
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• pp.103-108
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• 2007

In general, the swing motion of the crane is controlled and suppressed by activating the trolley motion. In many papers reported by us, we suggested a new type of anti-sway control system of the crane. In the proposed control system, a small auxiliary mass(moving-mass) is installed on the spreader and the swing motion is controlled by moving the auxiliary mass. The actuator reaction against the auxiliary mass applies inertial control forces to the container in order to reduce the swing motion in the desired manner. The measuring system is based on laser sensor or others. However it is not so useful in real world. Especially, in this paper, the image sensor is used to measures the motions of the spreader and the measured data are fed back to the controller in real time. The applied image processing technique is a kind of robust template matching method which is named Vector Code Correlation (VCC) and devised to consider the real environmental conditions. And the $H_{\infty}$ based control technique is applied to suppress swing motion of the crane. And the experimental result shows that the proposed measurement system based on image sensor and control system is useful and robust to disturbances.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.4
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• pp.101-109
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• 2020

PURPOSE: This study investigates the therapeutic effect of a prototype of a hand rehabilitation device based on magnetic forces. METHODS: Using an electromagnet and permanent magnets, we developed an end effector type device that induces various movements of the finger in accordance with the magnetic field direction. A total of 26 subacute stroke patients were enrolled and assigned to two groups in this randomized controlled trial. The intervention group received 30 minutes hand rehabilitation therapy per day for 4 weeks, using the device developed by us. Conventional physical therapies were conducted equally twice a day, 30 minutes per session, during the same period in both groups. RESULTS: After 4 weeks, rate of the Wolf Motor Function Test as a primary outcome measure showed significant improvement in the intervention group as compared to control group(p = .036). Scores of the Manual Function Test and Fugl-Meyer Assessment of upper limb were also significantly increased in the intervention group as compared to control group(p = .038 and p = .042, respectively). Moreover, the Korean version of Modified Barthel Index tended to improve after subjecting to physical therapy in both groups. CONCLUSION: Our results indicate that the novel hand rehabilitation device developed using a magnetic force, improves the hand motor functions and activities of daily life in subacute stroke patients.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.371-372
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• 2017

The United States has built a missile defense system from the Cold War era, but since the end of the Cold War era, there have been many changes in international situation and threats. The forces of power divided between the United States and the Soviet Union have become increasingly threatened by China's willingness to expand its external influence, declaration of strong Russia and North Korea and Iran's nuclear armament and advanced ballistic missile technology. In response to this threat change, the Missile Defense Agency(MDA) has established strategies and policies, but its parent law has not been revised. United States changed to the FY2017 National Defense Authorization Act (FY2017 NDAA) including changed missile defense strategy. In this paper, I check US ballistic missile defense strategies included in the FY2017 NDAA and compare what changes have been made in existing strategies.

• Journal of Construction Engineering and Project Management
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• v.8 no.1
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• pp.1-9
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• 2018

US transportation agencies are dealing with shrinking budgets, limited work forces, and deteriorating infrastructure. In order to cope with funding uncertainty, state highway agencies are now looking into their own organizations and identifying programs, practices, and processes that have potential for cost saving. A quality assurance (QA) program is an integral part of highway construction and ensures a project's contracted level of quality. The cost of quality (conforming and nonconforming) can constitute a sizable part of total construction cost. As the quality assurance programs evolved, various practices and processes were developed over time and later adopted by state highway agencies. These practices and processes include different QA standards and specifications, varying testing methods, central testing lab vs. on site testing, performance based vs. prescribed quality assurance practices, implementation of innovative quality assurance practices, etc. Therefore, there is an opportunity to assess different QA strategies and recommend those practices that are effective and cost efficient. A national survey was conducted by the authors, which provided a detailed mapping of various QA practices and processes used as part of QA programs and identified areas where agencies can focus on for cost savings. The survey found that QA sampling and testing plans, optimization of sampling plans, optimization of QA standards and specifications, and implementation of innovative test methods and processes are the main areas the agencies should focus to lean the current QA programs.

• Strategy21
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• s.44
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• pp.54-78
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• 2018

The core of the current constitutional amendment pursued by the Abe administration depends on the status of the Japanese Self-Defense Forces, which include the right to engage in war, in the legal and regular military positions. This is an important turning point for the Abe administration, which aims to become a normal country for Japan, and it is a series of steps that followed in the revision of the U.S. and Japan guidelines in 2015 and the overhaul of the security law in 2016. In this paper, we propose building "A navy Attractive to Alliances" as a way to secure Korea's maritime security under the current security environment. The term "attraction" refers to the alliance "first priority" especially in the United States. The way to do this is to transform the paradigm of the ROK-U.S. alliance into a naval hub in the vast seas, which will allow us to strengthen our national defense and even deter threats from neighboring countries. To this end, our navy needs to have a more active approach to U.S. East Asian strategy. If we can convince the United States to be a nation that contributes more to its East Asian strategy, it will only lead to a strengthening of the status of its alliance and expansion of its unilateral support and military capability against Japan, thus minimizing Japan's influence.