• Title/Summary/Keyword: D.P.R.K

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Power Attack against an Exponent Blinding Method (Exponent Blinding 기법에 대한 전력 공격)

  • Kim Hyung-Sup;Baek Yoo-Jin;Kim Seung-Joo;Won Dong-Ho
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 2006.06a
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    • pp.164-168
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    • 2006
  • 전력 공격은 암호화 연산 과정 중 발생하는 소비 전력의 파형을 측정하여 비밀 정보를 알아내는 공격 방식이다. 이러한 전력 공격에 대한 취약성을 막기 위하여 message blinding, exponent blinding과 같은 기법들이 적용되어 왔다. 본 고에서는 $ECC^{[1]}$암호화 연산 과정에서, r이 임의의 정수일 때, dP=(d-r)P+rP인 관계를 이용하는 exponent blinding기법$^{[2]}$에 대하여 언급하고, 위 기법을 전력 공격의 대응책으로 적용 시 적절히 구현되지 않으면 power attack에 대하여 매우 취약하다는 것을 보인다.

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Development of an Ultra-Slim System in Package (SiP)

  • Gao, Shan;Hong, Ju-Pyo;Kim, Jin-Su;Yoo, Do-Jae;Jeong, Tae-Sung;Choi, Seog-Moon;Yi, Sung
    • Journal of the Microelectronics and Packaging Society
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    • v.15 no.1
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    • pp.7-18
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    • 2008
  • This paper reviews the current development of an ultra-slim SiP for Radio Frequency (RF) application, in which three flip chips, additional passive components and Surface Acoustic Wave (SAW) filters are integrated side-by-side. A systematic investigation is carried out for the design optimization, process and reliability improvement of the package, which comprises several aspects: a design study based on the 3D thermo-mechanical finite element analysis of the packaging, the determination of stress, warpage distribution, critical failure zones, and the figuration of the effects of material properties, process conditions on the reliability of package. The optimized material sets for manufacturing process were determined which can reduce the number of testing samples from 75 to 2. In addition the molded underfilling (MUF) process is proposed which not only saves one manufacturing process, but also improves the thermo-mechanical performance of the package compared with conventional epoxy underfilling process. In the end, JEDEC's moisture sensitivity test, thermal cycle test and pressure cooker tests have also been carried out for reliability evaluation. The test results show that the optimized ultra-slim SiP has a good reliability performance.

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A Comparison of Performances for Growing Periods of Duck Breeders (육성 기간 중 종오리의 품종별 생산성 비교 연구)

  • Na, J.C.;Bang, H.T.;Park, S.B.;Yu, D.J.;Kim, H.G.;Kang, G.H.;Park, M.N.;Choi, H.C.;Suh, O.S.;Kang, H.K.
    • Korean Journal of Poultry Science
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    • v.36 no.2
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    • pp.133-137
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    • 2009
  • This study was conducted to evaluate the performance of Cherry Valley and Grimaud strain. A total of two hundred eighty eight, one day old duck breeders (Cherry Valley and Grimaud strain) were randomly divided into two groups with 4 replicates of 36 birds each and fed a commercially available diet for 24 weeks. Overall body weight gain was significantly higher in Cherry Valley (3,064 g) than in Grimaud strain (2,851 g). Feed intake was significantly increased in Grimaud strain compared with Cherry Valley strain (p<0.05). Viability of Grimaud strain showed 100.0% and was higher than that of Cherry Valley strain. Uniformity was not statistically different between Cherry Valley and Grimaud strains.

A Study on Fatigue Crack Propagation Behavior with Pure-Ti Plate (순수 티타늄 판재의 피로균열 전파거동에 관한 연구)

  • 오세욱;김태형;김득진;임만배
    • Journal of Ocean Engineering and Technology
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    • v.9 no.1
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    • pp.92-100
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    • 1995
  • The effect of different anisotropy and stress ratio on fatigue crack propagation behavior was investigated under various stress ratio(R=-0.4, -0.2, 0.2, 0.2, 0.4) using pure titanium sheet used in aerospace, chemical and food industry. The rack closure behavior under constant load amplitude fatigue crack propagation test was examined. Fatigue crack propagation rate da/dN was estimated in terms of effective stress intensity factor range, $\Delta$K$_{eff}$, regardless of various stress ratio but was influenced by anisotropy. Also, it was found that the effect of anisotropy was considerably decreased but still not negligible when he da/dN was evaluated by a conventional parameter, $\Delta$$K_{eff}$/E and when the modified da/dN.$\sqrt{\varepsilon}_f$ was evaluated by $\Delta$$K_{eff}$/E. On the other hand, da/dN could be evaluated uniquely by effective new parameter, $\Delta$K$_{eff}$/$sigma_{ys}$, regardless of anisotropy, as int he following equation da/dN=C''[\frac{{\Delta}K_{eff}}{{\sigma}_{ys}}]^{n''}. And effective stress intensity factor range ratio, U was estimated by the following equation with respect to the ratio of reversed plastic zone size, $\Delta r_{p}$ to monotonic plastic zone size, $r_p$ regardless of stress ratio and anisotropy. U=-4.45$(\Delta r_{p}/r_{p})^{2}$+4.1$(\Delta r_{p}/r_{p})$+0.245_{p})$+0.245

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Development of a 14.1 inch Full Color AMOLED Display with Top Emission Structure

  • Jung, J.H.;Goh, J.C.;Choi, B.R.;Chai, C.C.;Kim, H.;Lee, S.P.;Sung, U.C.;Ko, C.S.;Kim, N.D.;Chung, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.793-796
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    • 2005
  • A structure and a design of device were developed to fabricate large-scale active matrix organic light-emitting diode (AMOLED) display with good color purity and high aperture ratio. With these technologies, we developed a full color 14.1 inch WXGA AMOLED display. For the integration of OLED on an active matrix a-Si TFT backplane, an efficient top emission OLED is essential since the TFT circuitry covers a large position of the pixel aperture. These technologies will enable up the OLED applications to larger size displays such as desktop monitors and TVs.

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Relationships among Physical Activity Level, Health-promoting Behavior, and Physiological Variables in Korean University Students

  • Bang, Kyung-Sook;Song, Min Kyung;Park, Se-Eun;Kim, Hyungkyung
    • Perspectives in Nursing Science
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    • v.15 no.1
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    • pp.11-17
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    • 2018
  • Purpose: Many Korean college students suffer from physical inactivity and mental health problems. However, it has not been sufficiently reported how this lack of exercise and health-related behavior affect their health. The present study was performed to identify the relationships among physical activity level, health-promoting behavior, and physiological variables in Korean undergraduate and graduate students. Methods: Participants were 115 undergraduate and graduate students from one university in Seoul. The Pearson's correlation analysis was performed using SPSS for Windows. Results: Physical activity level had significant positive correlations with health-promoting behavior (r=.32, p=.001) and exercise self-efficacy (r=.25, p=.008), and health-promoting behavior had a significant correlation with depression (r=-.33, p<.001) and exercise self-efficacy (r=.44, p<.001). Additionally, physical activity level had significant correlations with triglyceride (r=-.20, p=.034) and vitamin D (r=.20, p=.029) levels. The high density cholesterol level had significant negative correlations with systolic blood pressure (r=-.33, p<.001), diastolic blood pressure (r=-.29, p=.002), and vitamin D (r=-.20, p=.035) levels. Conclusion: Physical activity level or health-promoting behavior had significant relationships with the health status of college students. Strategies need to be developed to improve health-promoting behaviors among college students.