• Structural Engineering and Mechanics
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• v.63 no.6
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• pp.847-856
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• 2017

Excessive vibrations can occur in long-span structures such as floors or footbridges due to occupant?s daily activity like walking and cause a so-called vibration serviceability issue. Since 1970s, researchers have proposed many human walking load models, and some of them have even been adopted by major design guidelines. Despite their wide applications in structural vibration serviceability problems, differences between these models in predicting structural responses are not clear. This paper collects 19 popular walking load models and compares their effects on structure?s responses when subjected to the human walking loads. Model parameters are first compared among all these models including orders of components, dynamic load factors, phase angles and function forms. The responses of a single-degree-of-freedom system with various natural frequencies to the 19 load models are then calculated and compared in terms of peak values and root mean square values. Case studies on simulated structures and an existing long-span floor are further presented. Comparisons between predicted responses, guideline requirements and field measurements are conducted. All the results demonstrate that the differences among all the models are significant, indicating that in a practical design, choosing a proper walking load model is crucial for the structure?s vibration serviceability assessment.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.4
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• pp.313-323
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• 2017

As vehicles become more intelligent this is focused on ways to enhance safety and convenience for both drivers and passengers. In particular, x-by-wire systems that replace rigid mechanical components with dynamically configurable electronic elements are being developed to expand intelligent functions, such as adaptive cruise control or lane departure warning system. Because the malfunction of safety-related modules controlling critical functions, such as brakes, throttle, and steering in x-by-wire systems, can cause injury or death, safety and reliability are the most critical issue for automotive vendors and parts manufacturers. In an effort to develop better and effective brake-by-wire system, this paper presents EMB system by using the low speed electric vehicle, which is not required large braking force, with motor controller. In addition, we design performance evaluation system of EMB with 1/4 low speed electric vehicle model and suggested EMB is evaluated through the performance evaluation system.

• Structural Engineering and Mechanics
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• v.63 no.3
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• pp.281-292
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• 2017

Architecture constraints in buildings may typically cause irregularities in the distribution of stiffness and mass and consequently causes non-compliance of centers of mass, stiffness and strength. Such buildings are known as asymmetric buildings the distribution of strength and stiffness is one of whose main challenges. This distribution is more complicated for concrete buildings with RC shear walls in which stiffness and strength are interdependent parameters. The flexibility under the foundation is another subject that can affect this distribution due to the variation of dynamic properties of the structure and its constituting elements. In this paper, it is attempted to achieve an appropriate distribution pattern by expressing the effects of foundation flexibility on the seismic demand of concrete shear walls and also evaluate the effects of this issue on strength and stiffness distribution among lateral force resistant elements. In order to understand the importance of flexibility in strength and stiffness distribution for an asymmetric building in different conditions of under-foundation flexibility, the assigned value to each of the walls is numerically calculated and eventually a procedure for strength and stiffness distribution dependencies on flexibility is provided.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.71
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• pp.85-105
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• 2016

Independent guarantee is new financial product developed in international commercial transaction. The nature of independent guarantee is an independent undertaking, which takes the form of documentary transaction. As long as the documents presented by the beneficiary are on their face complying with the terms and conditions of the guarantee, the guarantor is obliged to pay upon the complying presentation. Where parties choose to apply for issue of independent guarantee in international commercial transactions in China, Chinese court shall respect the autonomy of parties. If either the guarantor or the beneficiary is located outside of China, or the facts which cause the establishment, change or cancellation of independent guarantee relationship occurred outside of China, it shall be deemed as foreign related independent guarantee. If the interested parties requests for confirmation of the independence of foreign related independent guarantee, it shall be supported by Chinese court. However, parties dealing with Chinese domestic commercial transaction have not fully realized the severity of independent guarantee liability. The market credit is being cultivated and the financial innovation is being explored at present in China. In order to guard against the systematic and the regional financial risk, before relevant rules are promulgated, Chinese court shall not recognize the independence guarantees issued for the domestic commercial transaction, but treat it as joint liability surety.

• Korean System Dynamics Review
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• v.17 no.1
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• pp.77-105
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• 2016

Whenever Information leak case had been happened, even though IT Infra systems were reinforced, those cases of kind were not decreased. It meant that the causes are not only the fault of IT, but also other things. So that the information leak cases should have been studied by the interdisciplinary way. There was a point of view for the Business Ethics which needed to be studied in the interdisciplinary way. Financial Information Leak Case of three representative Card Companies in Korea which is happened in 2014 was a case which was composed by many problems. These were bad circumstances, half-educated, lower salary, and the most of all, the C-Levels' ignorance of the law. By studying the CLD: Causal Loop Diagram of Business Ethics and those mentioned factors, few meanings were discovered. Firstly, this case was not a accident, but a predeterminate issue at all, because of the structural unethical corruption. Secondly, main reason of this case was not only criminals who leaked information, but also managers, especially CEO who didn't obey the law, forced that to employees. Thirdly, although those companies had moral guide and did CSR activities, it was not help to protect this information leak case. This study shows that the important thing was not the action for showing, but effective action to management for sustainability.

• Journal of The Korean Digital Architecture Interior Association
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• v.13 no.3
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• pp.25-32
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• 2013

The elderly in South Korea in 2012 to 11.8% now aging fast-paced world, which is older than most countries. That is, as long as the elderly people lack the time to respond on the issue could cause many problems. According to the principle of social solidarity, long-term care insurance was introduced for the elderly since July 2008 and facility and sanction salaries were supported for the level 1 (the most serious illness) - level 3 (serious illness) elderly. On the other hand, in the fields of architecture, it is difficult to receive the contents of the unified related articles when the design and construction of the elderly welfare facilities take propel commissioned. This paper not only presents the elderly welfare facilities operated according to the institution and policy of elderly welfare facilities in terms of architecture, but also provides the criteria summarized by building facilities in the field of construction of elderly welfare facilities planning, planning, design is intended to provide basic information. This study addresses are as follows: First, the aging population of South Korea and welfare facilities for the elderly are addressed. Second, in terms of architecture, the institution and policy of elderly welfare facilities in South Korea, are addressed. Third, the construction criteria of elderly welfare facilities is summarized to help architectural practitioners understand. Fourth, the future direction of the architectural design of welfare facilities for the elderly is presented.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.802-808
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• 2011

One of the important mechanical properties of cryogenic temperature structure material is fracture toughness. Research on normalization of fracture toughness test method is becoming very important issue with development of cryogenic structural elements. Specially, mechanical properties estimation by each micro-structure of welding department is important because it can cause unstable fracture when use under cryogenic environment in case of welding department. In this study, fracture toughness estimation test was carried out to unloading compliance method and sensitization heat-tread minimized test specimen at liquid nitrogen (77K), liquid helium (4K), 293K temperature to STS-316L base metal and weld metal.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.300-306
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• 2009

Welding technology is applicable in many kinds of fields, with the help of its advantages such as easy operational procedure and structural simplification. However, in the process of welding, hazardous materials and fumes cause huge fire broke-outs, explosions, and health-conscious problems. Also, as heavy metals in fumes have a harmful effect on the environment, recently, this has emerged as a urgent social issue. This study has been aimed at the recommendation of the most environment-friendly, among materials currently used in plumbing welding, and it has been done at the result of the analysis of amount, ingredient, and size in collected fumes created in the experiment of welding five rods to galvanized steel pipes and steel pipe ones. At the test result, due to the effect of Zn-coating, galvanized steel pipes, when welded to rods, created more fumes than steel pipe ones. In the mean time, when it comes to welding rods, among five, WR-03 produced fumes the least. Therefore, a combination of the test results clearly indicates that the case of welding WR-03 to cast-iron pipes turned out to be the most environment-friendly.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.1
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• pp.113-123
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• 2017

Virtual reality technology is recognized as a next-generation technology and can create realistic environments like the real world and reproduce sensory experiences. And it is a cutting-edge technology that allows humans to experience the same real-world experience in a virtual world by computing the five senses with computers. Also Virtual reality is a technology that has the advantage of experiencing reality in cyberspace and is applied to content such as movies and games. However, many users who use virtual reality can feel cybersickness. And it especially in virtual reality games. This is an important issue for the virtual reality game industry to be resolved. Main symptoms of cyberscickness include dizziness, headache, and vomiting. Existing motion sickness and symptoms are similar, but the cause of cybersickness is different from traditional sickness. Therefore, this study uses virtual reality games and data from various organizations to determine the causes of cybersickness. Also, it intends to contribute to the development of the virtual reality game industry by presenting methods to supplement these problems.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.1
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• pp.79-85
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• 2017

Vehicular ad-hoc networks (VANETs) cause link disconnection problems due to the rapid speed and the frequent moving direction change of vehicles. Link disconnection in vehicle-to-vehicle communication is an important issue that must be solved because it decreases the reliability of packet forwarding. From the characteristics of VANETs, greedy forwarding protocols using the position information based on the inter-vehicle distance have gained attention. However, greedy forwarding protocols do not perform well in the urban environment where the direction of the vehicle changes greatly. It is because greedy forwarding protocols select the neighbor vehicle that is closest to the destination vehicle as the next transmission vehicle. In this paper, we propose a greedy anycast forwarding (GAF) protocol to improve the reliability of the inter-vehicle communication. The proposed GAF protocol combines the greedy forwarding scheme and the anycast forwarding method. Simulation results show that the GAF protocol can provide a better packet delivery rate than existing greedy forwarding protocols.