• Advances in aircraft and spacecraft science
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• v.5 no.3
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• pp.385-400
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• 2018

In this paper dynamic behavior (modal analysis and dynamic transient response) of a novel sandwich T-joint is numerically and experimentally investigated. An epoxy adhesive is selected for bonding purpose and making the step wise graded behavior of adhesive region. The effect of the step graded behavior of the adhesive zone on dynamic behavior of a sandwich T-joint is numerically studied. Finite element analysis (FEA) of the T-joints with carbon fiber reinforced polymer (CFRP) face-sheets is performed by ABAQUS 6.12-1 FEM code software. Modal analysis and dynamic half-sine transient response of the sandwich T-joint are presented in this paper. Two verification processes employed to verify the dynamic modeling of the manufactured sandwich panels and T-joint modeling. It has been shown that the step wise graded adhesive zone cases have changed the second natural frequency by about 5%. Also, it has been shown that the different arranges in the step wise graded adhesive zone significantly affect the maximum stresses due to transient dynamic loading by 1112% decrease in maximum peel stress and 691.9% decrease in maximum shear stress on the adhesive region.

• Proceedings of the CALSEC Conference
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• 1997.11a
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• pp.385-404
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• 1997

action items(1) ㆍ continuous support to develop AP214 by AP214 IS-registration ㆍ acquire STEP (AP214) implementation technologies through pilot development ㆍ step-wise implementation of AP214 processor toward practical use

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2459-2464
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• 2012

Many companies has led to the damage case being leaked to personal information by taking cyber attack. Also, planned hacking cases continues to increase for the purpose of acquiring monetary gain or causing social disruption induction, etc. Approximately 75% of the Web site attacks exploit the vulnerability of the application. Major security issue is to strengthen the S/W development security according to the legal basis. The members of the project team is the fact that the lack of recognition of application development security. In addition, passive response and security validation/testing, etc. throughout the SDLC to the entire area is insufficient. Therefore, rework due to the belated discovery of a defect has occurs. In this paper, we examine the case of the project step-by-step security activities by performing IT services companies. And, through this, we present security measures that can be applied to the step-wise real-world projects.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.4
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• pp.335-344
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• 2014

The safety case program has been prepared for the development of the disposal facility of low- and intermediate-level radioactive waste in Korea. For the development of the radioactive waste disposal facility, this program can be applied for the safety demonstration of the facility and for the safety judgment of development step based on the international standards and domestic development environment. Systematic safety approach of this program includes the safety strategies such as optimization, robustness, demonstrability and defense-in-depth principle which are based on the safety principle and objectives. From the quality of assessment basis, safety arguments focused on the uncertainty management and the confidence building can assure the disposal safety during the step-wise safety assessment.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.484-485
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• 1987

The characteristics of leader development in rod -to- plane air gap (20cm gap length) under positive impulse potentials have been studied by means of 2-photomultiplier technique and image intensifier camera. It was shown that the streamers radiate relatively short wavelength light (${\sim}340nm$) while the leaders radiate a plenty of long wave length light ($400{\sim}800nm$). It was also known that the streamers propagate very fast with a velocity of $6{\times}l0^7cm/sec$ but the leaders have average velocity of $5{\times}10^6cm/sec$ and they proceed gradually fast by step-wise development.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.167-176
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• 2005

Demand on the nuclear energy in East Asian countries has been grown rapidly to support economic development. After 9.11, nuclear security has become the world wide issue. In addition, unlike to other region, some countries are considering the introduction of nuclear power plants. To meet the challenges a new regional multilateral nuclear approach is proposed aiming at assurance of supply and non -proliferation. The new proposal is based on the principles of confidence building, volunteering, and incentives. The step wise approach is recommended to implement the multilateral system in East Asia.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.1
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• pp.69-80
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• 2002

This study aims to develop a potential centrality evaluation model (PCEM) which can evaluate the potential centrality of villages within the catchment boundaries. PCEM is a tool for evaluation of villages\` centralities by the potential centrality index (PCI) developed in this study. For quantification of PCI, total 31 evaluation criteria on the accessibility to other villages and the natural and human environment of the village were introduced. The weighting values of criteria were calculated from the step wise pair-comparision results of 14 specialists in academic fields on rural planning using by AHP (Analytic Hierachy Process) of MCE (multi-criteria evaluation) method. In the results, the weighting values of the spatial accessibility, the natural environments and the human environments were 448, 338 and 214, respectively, among total value being 1,000.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.33-44
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• 2007

This study proposed a Rural Amenity Values Assessment Model (RAVAM) to evaluate the rural amenity resources based on the Myun as a spatial unit. In RAVAM, 61 rural amenity resources were classified into almost intact nature resources, interaction between nature and man resources, man-made resources, respectively. Especially, Rural Scenic Value Index (RSVI) was developed to quantify rural scenic views as a rural amenity resource. RSVI was utilized in evaluation process of rural amenity resources. The weighing factors for the amenity resources were evaluated from the step wise pair-comparison results of 11 specialists by Analytic Hierarchy Process(AHP). In the results, the weighting values of almost intact nature resources, interaction between nature and man resources, man-made resources were 496, 323 and 181, respectively, among total value being 1,000.

• Journal of Information Technology Services
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• v.8 no.4
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• pp.41-55
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• 2009

Due to the global business environments and severe competitions, SMEs have carried out IS projects for their competitive advantages. However, numerous organizations have faced with difficulties in the IS project management such as large amounts of IT expenses and uncertainties in project implementations. Thus, this study is intended to discover critical risk factors in the IS project management. To achieve this research goal, we have mailed questionnaires to SMEs and SI companies that experienced IS project failures and 63 usual data were collected. The result of analysis with step wise regression showed that 6 factors are related with IS project failures. The study contributes to the literature in two ways. First, this paper empirically identifies IS risk factors for SME manufactures. Second, this research result can be utilized as a checklist for the successful IS implementations. Limitations and future research topics are also discussed.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.141-147
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• 2013

The purpose of this study was attempted to new methods in mammalian embryos vitrification. This method was affected to increase of the embryo vitrification efficiency and it would be applied to the field of embryo transfer to recipient by modified loading method of embryo into 0.25 ml plastic straw. The frozen mouse embryos were carried out warmed from two different cell stages (8-cell and blastocyst, respectively) by attachment of an embryo in the vitrification straw (aV) method. All groups were cultured in M-16 medium to determine the development and survivability for 24 h, respectively. Results shown that, the survivability of two different groups were significantly different (94.8% vs. 70.9%). Total cell number was not significantly different the non-frozen blastocyst ($99.7{\pm}12.4$) compared to the post-thaw blastocyst ($94.8{\pm}15.1$). From the 8-cell embryo, total cell number of frozen blastocysts were significantly lower than others groups ($74.7{\pm}14.6$, p<0.05). In the case of cell death analysis, the blastocysts from non-frozen and frozen-thawed 8-cell group were not different ($0.0{\pm}0.0$ vs. $1.9{\pm}3.1$, p>0.05). However, the apoptotic nuclei of blastocyst were significantly observed the frozen-thawed group ($5.4{\pm}4.4$) compared to non-frozen group (p<0.05). Therefore, this new method of embryos using in-straw dilution and direct transfer into other species would be more simple procedure of embryo transfer rather than step-wise dilution method and cryopreservation vessels, so we can be applied in animal as well as human embryo cryopreservation in further.