• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.171-174
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• 2004

In order to improve the damage tolerance of the conventional laminated composites, three­dimensional fiber structures incorporated with stitching yams have been utilized in this study. From the newly developed process termed as TAPIS(TApe Placement Incorporated with Stitching), carbon/epoxy composites have been fabricated. Two-dimensional composites with the same stacking sequence as 3D counterparts have also been fabricated for the property comparison. To examine the damage resistance performance the low speed drop weight impact test has been adopted. For the assessment of damage after the impact loading, specimens were subjected to C-scan nondestructive inspection compression after impact(CAI) were also conducted to evaluate residual compressive strength. Although the damage area of 3D composites was greatly reduced$(30-40\%)$ compared with that of 2D composites, the CAI strength did not show drastic improvement.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.110-114
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• 2009

This study is for the evaluation of compressive strength restoration of sandwich composite laminates with adhesively bonded scarf patches. It was used in this study that the sandwich composite laminate with an aluminum honeycomb core and CF1263 woven fabric carbon/epoxy faces was applied to the car body structure for Korean tiling train. In this study, it was damaged by low velocity impact and repaired using scarf repair method. Then, the compressive strength restoration of assessed by compressive after impact (CAI) test. From the test, it could be known that the compressive strength was restored up to 72% by only scarf repair method and 91% applied by an extra ply over the undamaged one.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.43-51
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• 1998

In this paper, the performance about the CDMA inital synchronization under the Rician fading channel, which is actively studied as a CAI for IMT2000(FPLMTS) is analyzed. Through the performance analysis with the double dwell serial search code acquisition, the minimum mean initial synchronization acquisition time vs signal detection threshold value and first dwell duration time respectively with parameters of false alarm probability, detection probability and test PN chips is presented and the results show the mean initial synchronization acquisition time is increased with lower slope than Rayleigh fading as the threshold value of the initial synchronization acquisition decision is increased.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.397-403
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• 2015

This paper presents a new SOC test compression scheme in Embedded Deterministic Test (EDT) compression environment. Compressed test data is brought over the TAM from the tester to the cores in SOC and decompressed in the cores. The proposed scheme allows cores tested at the same time to share some test channels. By sharing free variables in these channels across test cubes of different cores decompressed at the same time, high encoding efficiency is achieved. Moreover, no excess control data is required in this scheme. The ability to reuse excess free variables eliminates the need for high precision in matching the number of test channels with the number of care bits for every core. Experimental results obtained for some SOC designs illustrate effectiveness of the proposed test application scheme.

• Asia pacific journal of information systems
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• v.23 no.3
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• pp.25-53
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• 2013

This study analyzes the effect of Computer Aided Innovation (CAI) to improve R&D Capabilities empirically. Survey was distributed by e-mail and Google Docs, targeting CTO of 235 SMEs. 142 surveys were returned back (rate of return 60.4%) from companies. Survey results from 119 companies (83.8%) which are effective samples except no-response, insincere response, estimated value, etc. were used for statistics analysis. Companies with less than 50billion KRW sales of entire researched companies occupy 76.5% in terms of sample traits. Companies with less than 300 employees occupy 83.2%. In terms of the type of company business Partners (called 'partners with big companies' hereunder) who work with big companies for business occupy 68.1%. SMEs based on their own business (called 'independent small companies') appear to occupy 31.9%. The present status of holding IT system according to traits of company business was classified into partners with big companies versus independent SMEs. The present status of ERP is 18.5% to 34.5%. QMS is 11.8% to 9.2%. And PLM (Product Life-cycle Management) is 6.7% to 2.5%. The holding of 3D CAD is 47.1% to 21%. IT system-holding and its application of independent SMEs seemed very vulnerable, compared with partner companies of big companies. This study is comprised of IT infra and IT Utilization as CAI capacity factors which are independent variables. factors of R&D capabilities which are independent variables are organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability. The highest average value of variables was 4.24 in organization capability 2. The lowest average value was 3.01 in IT infra which makes users access to data and information in other areas and use them with ease when required during new product development. It seems that the inferior environment of IT infra of general SMEs is reflected in CAI itself. In order to review the validity used to measure variables, Factors have been analyzed. 7 factors which have over 1.0 pure value of their dependent and independent variables were extracted. These factors appear to explain 71.167% in total of total variances. From the result of factor analysis about measurable variables in this study, reliability of each item was checked by Cronbach's Alpha coefficient. All measurable factors at least over 0.611 seemed to acquire reliability. Next, correlation has been done to explain certain phenomenon by correlation analysis between variables. As R&D capabilities factors which are arranged as dependent variables, organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability turned out that they acquire significant correlation at 99% reliability level in all variables of IT infra and IT Utilization which are independent variables. In addition, correlation coefficient between each factor is less than 0.8, which proves that the validity of this study judgement has been acquired. The pair with the highest coefficient had 0.628 for IT utilization and technology-accumulating capability. Regression model which can estimate independent variables was used in this study under the hypothesis that there is linear relation between independent variables and dependent variables so as to identify CAI capability's impact factors on R&D. The total explanations of IT infra among CAI capability for independent variables such as organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability are 10.3%, 7%, 11.9%, 30.9%, and 10.5% respectively. IT Utilization exposes comprehensively low explanatory capability with 12.4%, 5.9%, 11.1%, 38.9%, and 13.4% for organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability respectively. However, both factors of independent variables expose very high explanatory capability relatively for technology-accumulating capability among independent variable. Regression formula which is comprised of independent variables and dependent variables are all significant (P<0.005). The suitability of regression model seems high. When the results of test for dependent variables and independent variables are estimated, the hypothesis of 10 different factors appeared all significant in regression analysis model coefficient (P<0.01) which is estimated to affect in the hypothesis. As a result of liner regression analysis between two independent variables drawn by influence factor analysis for R&D capability and R&D capability. IT infra and IT Utilization which are CAI capability factors has positive correlation to organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability with inside and outside which are dependent variables, R&D capability factors. It was identified as a significant factor which affects R&D capability. However, considering adjustable variables, a big gap is found, compared to entire company. First of all, in case of partner companies with big companies, in IT infra as CAI capability, organization capability, process capability, human resources capability, and technology capability out of R&D capacities seems to have positive correlation. However, collaboration capability appeared insignificance. IT utilization which is a CAI capability factor seemed to have positive relation to organization capability, process capability, human resources capability, and internal/external collaboration capability just as those of entire companies. Next, by analyzing independent types of SMEs as an adjustable variable, very different results were found from those of entire companies or partner companies with big companies. First of all, all factors in IT infra except technology-accumulating capability were rejected. IT utilization was rejected except technology-accumulating capability and collaboration capability. Comprehending the above adjustable variables, the following results were drawn in this study. First, in case of big companies or partner companies with big companies, IT infra and IT utilization affect improving R&D Capabilities positively. It was because most of big companies encourage innovation by using IT utilization and IT infra building over certain level to their partner companies. Second, in all companies, IT infra and IT utilization as CAI capability affect improving technology-accumulating capability positively at least as R&D capability factor. The most of factor explanation is low at around 10%. However, technology-accumulating capability is rather high around 25.6% to 38.4%. It was found that CAI capability contributes to technology-accumulating capability highly. Companies shouldn't consider IT infra and IT utilization as a simple product developing tool in R&D section. However, they have to consider to use them as a management innovating strategy tool which proceeds entire-company management innovation centered in new product development. Not only the improvement of technology-accumulating capability in department of R&D. Centered in new product development, it has to be used as original management innovative strategy which proceeds entire company management innovation. It suggests that it can be a method to improve technology-accumulating capability in R&D section and Dynamic capability to acquire sustainable competitive advantage.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.1
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• pp.62-67
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• 2011

Nanoparticles-coated and impact-damaged carbon-fiber reinforced plastics(CFRP) laminates were tested under compression-after-impact(CAI) mode and the propagation of damage due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. CFRP laminates were made of carbon prepregs prepared by coating of conductive nano-particles directly on the fibers and the coupons were subjected to simulated lightning strikes with a high voltage/current impulse of 10~40 kA within a few microseconds. The effects of nano-particles coating and the degree of damage induced by the simulated lightning strikes on the AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terms of damage area by using ultrasonic C-scan images. From the results assessed during the CAI tests of damaged CFRP showed that AE monitoring appeared to be very useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes.

• Journal of The Korean Association For Science Education
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• v.27 no.5
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• pp.412-420
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• 2007

In this study, we investigated the influences of the epistemological beliefs on the conceptual change processes in respects of cognitive conflict, situational interest, attention and state learning strategies. After administering epistemological belief questionnaire as a pretest, 218 seventh graders possessing misconceptions about density were selected from the results of a preconception test. The questionnaires of responses to a discrepant event and situational interest were administered. After learning with a CAI program, attention test, state learning strategy test and conception test were also administered as post-tests. Analysis of the results revealed that fixed ability, quick learning and certain knowledge, which are epistemological factors, were highly related, but only certain knowledge exerted a direct effect on conceptual understanding negatively. It also had positive effects on attention directly as well as via situational interest, and thus increased conceptual understanding, even if the effects were relatively smaller than the direct effect. However, epistemological beliefs had little influence on conceptual understanding through cognitive conflict and/or state learning strategies.

• Journal of the Korean Statistical Society
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• v.32 no.2
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• pp.163-174
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• 2003

We propose a test for independence of bivariate censored data under univariate censorship. To do this, we first introduce a process defined by the difference between bivariate survival function estimator proposed by Lin and Ying (1993) and the product of the product-limit estimators (Kaplan and Meier, 1958) for the marginal survival functions, and derive its asymptotic properties under the null hypothesis of independence. We propose a Cramer-von Mises-type test procedure based on the process . We conduct simulation studies to investigate the finite-sample performance of the proposed test and illustrate the proposed test with a real example.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.463-469
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• 2016

This paper presents a compression-friendly low power test scheme in EDT environment. The proposed approach exploits scan slices reusing to reduce the switching activity during shifting for test scheme based on linear decompressor. To avoid the impact on encoding efficiency from resulting control data, a counter is utilized to generate control signals. Experimental results obtained for some larger ISCAS'89 and ITC'99 benchmark circuits illustrate that the proposed test application scheme can improve significantly the encoding efficiency of linear decompressor.

• The Journal of Korean Academic Society of Nursing Education
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• v.10 no.2
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• pp.239-251
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• 2004

The purpose of this study was to find out the effects of education for prevention of child sexual abuse (rape, sexual assault, sexual harassment etc.) of children in elementary school students. Incidences of sexual abuse in Korea is ranked 3rd in the world. Sexual abuse of children, particularly, is one of the most serious crimes that affect both the victimized children and their family. The issue related to sexual abuse of children has been ignored, and there is a lack of systematic education to prevent sexual abuse of children either for children or their parents. Furthermore, lack of knowledge and poor attitude of teachers limit their capability to provide education for sexual abuse prevention to the children. The education for teachers may change their knowledge of the sexual abuse and their attitude toward it and improve their capability in helping children. 223 Korean elementary school students participated in this study. Research design was One group pretest-posttest design. The education given to the subjects included 4 hours through the multimedia CD-ROM on the prevention of child sexual abuse. The education program was developed based on a survey. School- aged- children, parents, and teachers were interviewed to reveal their educational needs based on their experiences related to sexual abuse. This program includes such as safety education, crisis management, resource person(s), and phone numbers of available hospital. Data was collected before, during and after the education was given to the subjects, to assess their knowledge and attitude toward child sexual abuse. Two instruments were used in this study. Using Cronbach's ALPHA validity and reliability of 2 instruments were tested. The analysis of the data was done with Window SPSS 10.0 for descriptive statistics, t-test and ANOVA. The results of this analysis were as follows : 1. After education, the score of school nurses knowledge was higher than before(t= -4.677, p=0.000). 2. After education, the score of school nurses attitude was not higher than before (t=0.131, p=0.896). The findings from this study will provide an intervention strategy for prevention of sexual abuse in children.