• Convergence Security Journal
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• v.12 no.2
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• pp.107-113
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• 2012

Recently, according to the establishment of personal information protection Act, the public and private organizations are taking a step to protect personal information rights and interests by employing the technical methods such as the access control mechanism, cryptography, etc. The result of the personal information leakage causes a serious damage for the organization image and also has to face with the responsibility by law. However, applying access control and cryptographic approach on the personal information item for every connection to large database system causes significant performance degradation in a large database system. In this paper, we designed and implemented the light weight system using JVM (Java Virtual Machine) for the Oracle DBMS environment which the concurrent transaction occurs many, thereby the proposed system provides the minimum impact on the system performance and meets the need of personal information protection. The proposed system was validated on the personal information protection system which sits on a 'A' public organization's portal site and personnel information management system.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.163-170
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• 2000

Accident statistics shows that the portion of fatal occupant injuries due to side impacts is considerably high. The side impact usually leads to a severe intrusion of side structure into the passenger compartment. Furthermore, the safety zone for the side impact is relatively small compared to the front impact. Those kinds of physics for side impact frequently result in a fatal injury for the occupant. Therefore, NHTSA and EEVC are trying to intensify the regulation for the occupant protection against side impact. Both the regulation and recent market trends are asking for an installation of side airbag. There are several types of system configuration for side impact sensing. In this paper, we adopt the acceleration-based remote sensing method for the side airbag control system. We mainly focus on the development of hardware and crash discrimination algorithm of remote sensing unit. The crash discrimination algorithm needs fast decision of airbag firing especially for high-speed side impact such as FMVSS 214 and EEVC tests. It is also required to distinguish between low-speed fire and no-fire events. The algorithm should have a sufficient safety margin against any misuse situation such as hammer blow, door slam, etc. This paper introduces several firing criteria such as acceleration. velocity and energy criteria that use physical value proportional to crash severity. We have made a simulation program by using Matlab/Simulink to implement the proposed algorithm. We have conducted an algorithm calibration by using real crash data for 2,500cc vehicle. The crash performance obtained by the simulation was verified through a pulse injection method. It turned out that the results satisfied the system requirements well.

• Wind and Structures
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• v.17 no.2
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• pp.185-202
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• 2013

The goal of this study was to investigate the vulnerability of roof tile systems and metal shutters to roof tile debris. Three phases addressed the performance of tile roof systems and metal shutters impacted by roof tile debris. The first phase experimentally evaluated the tile fragment size and quantity generated by a tile striking a tile roof system. The second phase experimentally quantified the puncture vulnerability of common metal panel shutter systems as a function of tile fragment impact speed. The third phase provided context for interpretation of the experimental results through the use of a tile trajectory model. The results provide supporting evidence that while metal panel window shutters provide significant protection against a prevalent form of windborne debris, these systems are vulnerable to tile fragment puncture in design level tropical cyclones. These findings correlate with field observations made after Hurricane Charley (2004).

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.153-154
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• 2015

Voltage Source Converter HVDC (VSC-HVDC) are a better alternative than conventional thyristor based HVDC systems. Unfortunately, VSC-HVDC's full potential cannot be utilized up till now due to absence of suitable HVDC protection. Recently, hybrid HVDC circuit breakers (HDCCB) have been developed and successfully lab tested. However, their application and feasibility in VSC-HVDC needs to be investigated. In this research paper we have modelled an existing HDCCB and evaluated its impact on fault reduction and interruption in VSC-HVDC systems. The HDCCB was applied in Korean Jeju-Haenam VSC-HVDC system model and its impact was analyzed for HVDC line-to-ground and line-to-line faults. HDCCB successfully interrupted the fault current and prevented the damages to costly IGBTs and converter transformers.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.753-760
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• 2007

For protection of the cylinder wall of the ball mill for grinding raw ore. the inner side of the cylinder is covered with rubber liner. The rubber is easily worn down because the rubber relatively soft compared with raw ore. So the rubber liner in the ball mill cylinder must be replaced almost every year and the cost for replacing rubber liner formidable. In this paper, for reducing or excluding the cost of replacing rubber liner the basalt liner is designed. The basalt materials are generally harder than raw ore and the basalt liner in the ball mill does not wear down and so it can be used almost permanently. The concave surfaces are made on the liner of the ball mill and the liner in the cylinder wall plays also the role of raising the steel balls mixed in the raw ore. The section profiles of the concave surface have an important effect on the performance of the ball mill. The deep concave grooves raise the steel balls to high levels and give the large potential energy to the steel balls impacting to the raw ore. But if the concave grooves are too deep. the steel balls raised too high by the concave grooves fly along the parabolic path and reach to the other side of cylinder wall and so the steel balls do not play the roles of grinding the raw ore. The forces acting to a steel ball in a concave groove of the cylinder liner are also analyzed in this paper. The formulas calculating the height and the impact point of the steel ball are introduced and presented. Based to these formulas, the optimum section profiles of the basalt liner are presented.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1453-1459
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• 2015

Loss of excitation (LOE) relay is prevalently used to protect synchronous generator. The widely used method for synchronous generator LOE protection is a negative offset mho relay with two zones. The basis of this relay is identical to mho impedance relay. In other words, this relay calculates impedance by measuring voltage and current at the generator terminal. On the other hand, the presence of series compensation, changes measured voltage and current signals during loss of excitation. This paper reveals that the presence of series compensators such as fixed series capacitors (FSCs) and static synchronous series compensator (SSSC) causes a significant delay on the performance of generator LOE relay. It is also shown that the presence of SSSC causes the LOE relay to be under-reached. Different operating modes of the power system, the SSSC and also different percentages of series capacitive compensations have been considered in the modeling. All the detailed simulations are carried out in the MATLAB/Simulink environment using the SimPowerSystems toolbox.

• Journal of Korean Society for Quality Management
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• v.47 no.2
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• pp.283-294
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• 2019

Purpose: Although the development of bulletproof helmets continues to be carried out, little has been improved in testing methods. Therefore, in this study, we studied the improvement of the test method of the domestic bulletproof helmet. Methods: The causes of head damage in the battlefield and the trends of bulletproof helmet development in developed countries were analyzed. In addition, improvements were derived by comparing the test methods of bulletproof helmet in Korea and the United States. Results: The results of the improvement by comparing the test methods of bulletproof helmet in Korea and the United States are as follows First, it is an addition to the scope of environmental treatment. Second, it is an addition to the level of protection. Third, the addition of the level of protection by impact. Conclusion: This study considered testing methods to prevent head injuries to shocks that cannot be identified by conventional methods. In addition, it considered testing methods for various threats by improving protection performance to advanced countries' levels.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.465-473
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• 2013

Concrete is an outstanding material in terms of its impact and blast resistance performance. However, there a limitation of concrete is its risk of collapse due to the brittle failure and spalling. Increasing the thickness of members was used as a method to enhance the protective performance of concrete, despite the resulting inefficient space. To solve this problem, different types of fiber reinforced concrete were developed. Recently, another type of fiber reinforced concrete is also being developed and applied as a material that offers protection against impacts and blasts by increasing the flexural toughness of concrete. In this study, the test was conducted to evaluate the impact resistance performance of fiber reinforced concrete and mortar according to impact of high-velocity projectile. A concrete T-wall was also tested to evaluate its protective performance from fragment by 155mm-thick artillery shell. The test results revealed that improving flexural strength through fiber reinforcement inhibited cracks and spalling of rear, and spalling of front by high-velocity impact. As such, it is expected to improve the protective performance of the T-wall and reduce the thickness of the member.

• The Journal of Information Systems
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• v.10 no.2
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• pp.165-192
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• 2001

Knowledge Management (KM) is the systematic, explicit, and deliberate building, renewal, and application of knowledge to maximize an enterprise's knowledge-related effectiveness and performance from its knowledge assets. KM applies systematic approaches to find, understand, and use knowledge to create new capabilities, solve problems, enable superior performance, and encourage innovation. The purpose of this research is to identify the relationship of KM capabilities (KM infrastructures and KM processes) and organizational effectiveness and performance. An empirical research of the relationship of knowledge management capabilities and organizational effectiveness and performance is conducted from the information systems and knowledge management literature in order to access the following questions: (1) Does the knowledge management infrastructure contribute to the organizational effectiveness and peformance? (2) Does the knowledge management process contribute to the organizational effectiveness and peformance? The research design employs a mail survey questionnaire for gathering data from 500 firms in a number of industries. From a mail survey of 61 top managers of knowledge management, the results of empirical analyses provide the following major findings: (1) While the external effectiveness of organization is influenced by the cultural infrastructure of knowledge management, the overall performance of organization is influenced by the structural infrastructure of knowledge management. (2) While the external effectiveness of organization is influenced by the application and protection processes of knowledge management, the overall performance of organization is influenced by the knowledge acquisition process of knowledge management.

• Journal of Distribution Science
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• v.12 no.10
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• pp.57-65
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• 2014

Purpose - This study aims to identify the effect of corporate eco-friendly marketing, which focuses on corporate social responsibility, on the environment, natural preservation and protection, and environmental concern among consumers. Research design, data, and methodology - A total of 92 valid questionnaires were used for analysis. A structured model was established and a 3-step mediated regression test was employed to see how consumers' perception of ethical consumer behavior and price sensitivity are influential in relation to the impact of consumer's perception of eco-friendliness on the using intention in relation to eco-friendly products. Results - Three factors of eco-friendly perception all have a positive impact on ethical consumer behavior, thus lowering their price sensitivity. In particular, it is found that environmental knowledge and environmental concern are important to promote ethical consumer behavior. Conclusion - It is found that, to increase the using intention of eco-friendly products, an enterprise should practice an eco-friendly marketing strategy, deliver eco-friendly related knowledge, and include contents to allow consumers to take an interest in the environment for effective performance of marketing.