• 조명전기설비학회논문지
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• 제20권9호
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• pp.78-83
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• 2006

A new measure, the distributed generation impact factor (DGIF), is used for evaluating the impact of newly introduced distributed generators on a networked distribution or a transmission system. Distribution systems are normally operated in a radial structure. But the introduction of distributed generation needs load flow calculation to analyze the networked system. In the developed framework, the potential share of every generation bus in each line flow of a networked system can be directly evaluated. The developed index does not require the solution of power flow equations to evaluate the effect of the distributed generation. The main advantage of the developed method lies in its capability of considering simultaneous outputs of multiple generation sites.

• 한국군사과학기술학회지
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• 제13권4호
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• pp.511-519
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• 2010

This paper presents the modeling and validation of a pile-driver breech fatigue testing system model to replicate actual high pressure in a large caliber gun barrel. A hysteresis damping function was incorporated in the nonlinear impact force model. Test of real pile-driver breech fatigue testing system had been performed for model validation. Comparison of the experimental result and model simulation during impact were made. Numerical studies were performed to evaluate how the actual chamber pressure pattern in the live firing of gun barrel was affected by parameters' variation. Some of the parameters simulated included input velocity, damping coefficient and stiffness. As a result, a variety of actual chamber pressure pattern could be reproduced and controlled through current simulation model.

• 농촌지도와개발
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• 제17권4호
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• pp.933-955
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• 2010

Researchers have different views on impact of information system use on productivity. The differences are fueled by 'the productivity paradox' insisted by Brynjofsson(1993). This paper intend to quantitate impacts of information system and to test the productivity paradox of using the information system. Restricted Maximumlikelihood Estimation(RMLE) method is applied on data from 81 farms adopting Pigplan system. The results find positive productivity improvement with information systems in swine farm. Adopting Pigplan system increases 0.52 in PSY(pigs per sow per year) and 0.087 in sow turnover. When it comes to region and farm size, region has impact on both PSY and sow turnover, while farm size does not. This result infers that local cooperatives, regardless of farm size, differentiate the impacts of the information system, implying that the ability to utilize information systems should be improved in organizational level.

• 환경영향평가
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• 제13권2호
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• pp.57-71
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• 2004

This study aims to review the environmental impact assessment systems of Japanese local governments, to compare its outcome with the systems of Korean local governments, and to suggest the development direction for the environmental impact assessment systems of Korean local governments based on the result. The study results showed that, first, due to distinction in the political systems of Japan and Korea, while Japan has bottom-up environmental impact assessment systems, Korea has topdown environment impact assessment systems. Second, although introduction of national systems on planning was put on hold as a future initiative, local governments including Tokyo and Saitama are experimenting evaluation procedures tailored to local features by legislating them as regulations. On the other hand, while 'prior environmental review system' was in effect as a national system, nothing was practiced at all by local governments. Third, in a total of 47 Japanese local governments, about 45 projects and 44 assessment items were added to local government environmental impact assessment only and designated as target projects and assessment items. Fourth, in both national and local environment impact assessment systems in Japan, screening procedures to determine assessment by separating into Type 1 projects and Type 2 projects and scoping procedures to discuss assessment items in advance were introduced and in effect. This Japanese EIA system may serve as a good reference to the Korean national and local government EIA systems.

• 환경영향평가
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• 제2권2호
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• pp.73-83
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• 1993

Increasing concern for the environment in Korea has led to the demand that major policies and large-scale development projects be subjected to detailed impact assessment. This paper reports on the state of data related to the prediction of the environmental impact (EIA) to emphasize the importance of data quality. Environmental impact statements (EIS) consulted with the Ministry of Environment of Korea were analyzed from 1981 through 1992. Many of assessors used existing data and collected supplementary data from field survey. Most of the results of EIA are presented directly or summarized on maps and as graphics. For the national purpose, large source of quality-controlled data such as atmospheric data have been developed, However, there are the deficiency in data to analyze the impact of human activity, and data gaps and incompatibilities among systems. Consequently, the development of data bank systems including computer database and remotely-sensed satellite data is required to improve the quality of data which are relevant to EIA. The data bank system should be organized meaningfully in minimum time with a least cost, and measurement standards must be made explicit. Geographical information systems (GIS) are applicable to the graphic presentation or to the impact prediction model.

• 동력기계공학회지
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• 제9권4호
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• pp.137-142
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• 2005

The effects of temperature and initial crack length on impact fracture behavior of side plate material of 35 ton class FRP ship, which are composed by glass fiber and unsaturated polyester resin, were investigated. Impact fracture toughness of GF/PE composites displayed maximum value when the temperature of specimen is room temperature and $50^{\circ}C$, and with decrease in temperature of specimen, impact fracture toughness decreased. Impact fracture energy of GF/EP composites decreased with increase in initial crack length of specimen, and this value decreased rapidly when the temperature of specimen is lowest, $-25^{\circ}C$,. It is believed that sensitivity of notch on impact fracture energy were increased with decrease in temperature of specimen. As the GF/EP composites exposed in low temperature, impact fracture toughness of composites decreased gradually owing to the decrease of interface bonding strength caused by difference of thermal expansion coefficient between the glass fiber/polyester resin. Further, decrease of interface bonding strength of composites with decrease in specimen temperature was ascertained by SEM photograph of impact fracture surface.

• Journal of Information Processing Systems
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• 제6권4호
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• pp.597-608
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• 2010

Software evolution is an ongoing process carried out with the aim of extending base applications either for adding new functionalities or for adapting software to changing environments. This brings about the need for estimating and determining the overall impact of changes to a software system. In the last few decades many such change/impact analysis techniques have been developed to identify consequences of making changes to software systems. In this paper we propose a new approach of estimating change/impact analysis by classifying change based on type of change classification e.g. (a) nature and (b) extent of change propagation. The impact set produced consists of two dimensions of information: (a) statements affected by change propagation and (b) percentage i.e. statements affected in each category and involving the overall system. We also propose an algorithm for classifying the type of change. To establish confidence in effectiveness and efficiency we illustrate this technique with the help of an example. Results of our analysis are promising towards achieving the aim of the proposed endeavor to enhance change classification. The proposed dynamic technique for estimating impact sets and their percentage of impact will help software maintainers in performing selective regression testing by analyzing impact sets regarding the nature of change and change dependency.

• Steel and Composite Structures
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• 제44권1호
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• pp.105-117
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• 2022

Impact resistance efficiency of the newly designed sandwich beam with a laterally arched core as bio-inspired by the woodpecker is numerically investigated. The principal components of the beam comprise a dual-core system sandwiched by the top and bottom laminated CFRP skins. Different materials, including hot melt adhesive, high-density polyethylene (HDPE), acrylonitrile butadiene styrene (ABS), epoxy resin (EPON862), aluminum (Al6061), and mild carbon steel (AISI1018), are considered for the side-arched core layer of the beam for impact efficiency assessment. The aluminum honeycomb takes the role of the second core. Contact force, stress, damage formation, and impact energy for beams equipped with different materials are examined. A diversity in performance superiority is noticed in each of these indicators for different core materials. Therefore, for overall performance appraisal, the impact resistance efficiency index, which covers several chief impact performance parameters, of each sandwich beam is computed and compared. The impact resistance efficiency index of the structure equipped with the AISI1018 core is found to be the highest, about 3-10 times greater than other specimens, thus demonstrating its efficacy as the optimal material for the bio-inspired dual-core sandwich beam system.

• 항공우주시스템공학회지
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• 제6권4호
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• pp.29-33
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• 2012

This paper is focusing on the difference from experiment result and method through dynamic loaded from impact analysis about inertia measure unit of high speed projectile. At Inertia measure unit dynamic load is applied when the high speed projectile is operated by impact to inside. it is necessary to design inertia measure unit enduring from external effect with operating environment. Investigation of material deformation with high strain speed is performed for military purpose, and still concerned to many scientist. From this study, this paper will prove of impact analysis result through comparing with experiment result and method when applied dynamic load.

• 환경영향평가
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• 제9권4호
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• pp.315-322
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• 2000

Environmental Impact Assessment(EIA) was first formally established in the Korea in 1981. Subsequently there has been a rapid growth in EIA activity, and over one hundred fifty environmental impact statements are now published in Korea each year. Although EIA now has almost 20 years of history in the Korea, elsewhere the development of roles and practice is more recent. Development is moving apace in many countries, including the Japan and the EU Member States. Such progress has not been without its problems, and a number of the current issues in EIA-scope of the assessment, the relative roles, the quality of assessment and monitoring and auditing after decision, and so on- are highlighted. So the purpose of this article is to reform the EIA roles and process, in extending the scope of activity, and assessing effectiveness. This article suggested improving the effectiveness of project assessment, widening the scope: stretegic environmental assessment, and extending EIA to project design process, environmental monitoring and feedback system.