• 제목/요약/키워드: S&T

검색결과 37,445건 처리시간 0.053초

MnO2, Fe2O3 첨가에 따른 0.05Pb(Al2/3W1/3)O3-0.95Pb(Zr0.52Ti0.48)O3계의 유전 및 압전 특성에 관한 연구 (The Study of the Dielectric and Piezoeletric Properties of 0.05Pb(AlS12/3TWS11/3T)OS13T-0.95Pb(ZrS10.52TTiS10.48T)OS13T System Modified with MnOS12T and FeS12TOS13T)

  • 윤석진;오현재;정형진
    • 대한전기학회논문지
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    • 제41권5호
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    • pp.508-516
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    • 1992
  • In this study, dielectric and piezoelectric properties of 0.05Pb(AlS12/3TWS11/3T)OS13T-0.95Pb(ZrS10.52TTiS10.48T)OS13T system ceramics were investigated with respect to the variations of MnOS12T and FeS12TOS13T additions amounts. The results obtained in this study are summarized as follows: 1. As the amounts of MnOS12T and FeS12TOS13T are increased, tetragonality(c/a) and apparent density were decreased but grain size was increased, also the limits of solubility were revealed because pores were formed at the amounts of 0.3wt% MnOS12T and 0.5wt% FeS12TOS13T. 2. AS the increasing of amounts of MnOS12T and FeS12TOS13T, the temperature of phase transition(TS1cT) was decreased, and pemeability had maximum value at the amount of 0.3wt% MnOS12T but were sharply decreasd for the increasing FeS12TOS13T amounts. 3. As the amounts of MnOS12T and FeS12TOS13T are increased, the electro-mechanical coupling factor(kS1pT) was decreased from 60% to 41%, 19% respectively, but mechanical quality factor(QS1mT) had maximum values 720 for amount of 0.3wt% MnOS12T and 320 the amount of 0.5wt% FeS12TOS13T.

Spectral Properties of k-quasi-class A(s, t) Operators

  • Mecheri, Salah;Braha, Naim Latif
    • Kyungpook Mathematical Journal
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    • 제59권3호
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    • pp.415-431
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    • 2019
  • In this paper we introduce a new class of operators which will be called the class of k-quasi-class A(s, t) operators. An operator $T{\in}B(H)$ is said to be k-quasi-class A(s, t) if $$T^{*k}(({\mid}T^*{\mid}^t{\mid}T{\mid}^{2s}{\mid}T^*{\mid}^t)^{\frac{1}{t+s}}-{\mid}T^*{\mid}^{2t})T^k{\geq}0$$, where s > 0, t > 0 and k is a natural number. We show that an algebraically k-quasi-class A(s, t) operator T is polaroid, has Bishop's property ${\beta}$ and we prove that Weyl type theorems for k-quasi-class A(s, t) operators. In particular, we prove that if $T^*$ is algebraically k-quasi-class A(s, t), then the generalized a-Weyl's theorem holds for T. Using these results we show that $T^*$ satisfies generalized the Weyl's theorem if and only if T satisfies the generalized Weyl's theorem if and only if T satisfies Weyl's theorem. We also examine the hyperinvariant subspace problem for k-quasi-class A(s, t) operators.

마늘약과의 개발에 관한 연구 1. 마늘즙 대체량을 달리한 마늘약과의 품질특성 (A Study of Garlic-Yackwa Development 1. Quality Characteristics of Garlic-Yackwa Substituted with Different Amounts of Garlic Juice)

  • 문숙임
    • 한국식품영양과학회지
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    • 제32권8호
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    • pp.1285-1291
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    • 2003
  • 본 연구는 마늘약과의 개발을 위한 일환으로 최적량의 마늘즙 대체량을 알아내기 위해 대체량을 달리하여 5가지 대체약과군을 만들어 생강즙 첨가 약과군과 색도, 기계적 품질 특성, 관능평가를 비교 실시하여 다음과 같은 결과를 얻었다. L값(명도)은, 마늘즙 0t.s 대체군이 가장 높았고. 마늘즙 2t.s 대체군이 가장 낮았다. 마늘즙 대체군들(1/2 ∼ 2t.s)은 생강즙 첨가군보다 낮았고, 대체량이 증가할수록 명도는 감소하는 경향이었다. a값(적색도)은 마늘즙 0t.s 대체군이 가장 높았고, 마늘즙 2t.s 대체군이 가장 낮았다. 대체군들(1/2 ∼ 2t.s)은 생강즙 첨가군보다 낮았고, 대체량이 증가할수록 적색도는 감소하는 경향이었다. b값(황색도)은 생강즙 2t.s 첨가군이 가장 높았고, 마늘즙 0t.s 대체군이 가장 낮았다. 대체군들(0 ∼ 2t.s)은 생강즙 2t.s 첨가군보다 낮았고, 대체량이 증가할수록 황색도도 증가하는 경향이었다. 경도는 생강즙 2t.s 첨가군이 가장 높았고, 마늘즙 0t.s 대체군이 가장 낮았다. 마늘즙 대체군들(1/2 ∼ 2t.s)은 생강즙 첨가군보다 유의적으로 낮았고, 마늘즙 대체이 증가할수록 경도도 증가하였다. 부착성은 생강즙 2t.s첨가군이 가장 높았고, 마늘즙 2t.s 대체군이 가장 낮았다. 마늘즙 대체군들(1/2 ∼ 2t.s)은 생강즙 첨가군보다 유의적으로 낮았다. 탄력성은 마늘즙 0t.s 대체군이 가장 높았고, 생강즙 2t.s 첨가군이 가장 낮았다. 마늘즙 대체군들(0 ∼ 2t.s)은 생강즙 첨가군보다 유의적으로 낮았고, 대체량이 증가할수록 감소하는 경향이었다. 응집성은 마늘즙 2t.s 대체군이 가장 높았고, 마늘즙 0t.s대체군이 가장 낮았다. 마늘즙 대체군들(0t.s ∼ 2t.s)은 생강즙 첨가군보다 유의적으로 높았고, 대체량이 증가할수록 응집성이 증가하는 경향이었다. 점착성은 마늘즙 2t.s 대체군이 가장 높았고, 마늘즙 0t.s 대체군이 가장 낮았다. 마늘즙 대체군들은 생강즙 첨가군보다 높거나(1$\frac{1}{2}$t.s, 2t.s) 낮았고(0 ∼ lt.s), 대체량이 증가할수록 점착성이 증가하는 경향이다. 씹힘성은 생강즙 2t.s첨가군이 가장 높았고, 1$\frac{1}{2}$t.s대체군이 가장 낮았다. 마늘즙 대체군들(0 ∼ 2t.s)은 생강즙 첨가군보다 낮은 값을 보였으며, 대 체량이 증가할수록 씹힘성은 감소하는 경향이었다. 관능평가에서, 마늘즙 대체량이 많을수록 색, 모양, 향, 맛, 전반적인 선호도가 좋았고, 특히 마늘즙 2t.s 대체군이 색, 모양, 맛, 전반적 인 선호도가 가장 좋았다. 질감은 마늘즙 2t.s 대체군이 가장 좋게 평가되었고, 생강즙 2t.s 대체군이 가장 나쁘게 평가되었다. 결론적으로, 마늘약과 제조시 밀가루 1컵당 2t.s의 마늘즙을 생강즙 대신 넣는 것이 가장 바람직하다고 생각된다.

과학기술인의 종합복지 제고 전략: 과학기술인 종합복지타운 건립을 중심으로 (How to Improve the Welfare of Science & Technology Personnel: Based on the Construction of Comprehensive Welfare Town for S&T Personnel)

  • 정선양;이종민
    • 기술혁신연구
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    • 제14권3호
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    • pp.155-182
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    • 2006
  • Science & Technology(S&T) personnel have been Playing a major role to develop our country since S&T is the most important factor in enhancing national competitiveness in the 21st century, As S&T activities are done by S&T personnel, it is essential to improve the welfare of S&T personnel in order to increase the performance of S&T activities. We should motivate them to pour their efforts and energy in S&T activities. However, the issue of S&T personnel's welfare has not been discussed sufficiently not only in academic research, but also in actual S&T policies. It has caused many social problems, for example, avoidance of S&T areas by young generation, low social recognition of S&T community, and so on. Under this background, this paper aims at investigating how to effectively improve S&T personnel's welfare. In this paper, we will suggest the 'Comprehensive Welfare Town for S&T personnel' as an effective instrument for improving of S&T personnel's welfare. In particular, we will discuss the detailed aspects of the comprehensive welfare town : objectives, strategies and budgets.

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EXTENSIONS OF NAGATA'S THEOREM

  • Hamed, Ahmed
    • 대한수학회지
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    • 제55권4호
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    • pp.797-808
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    • 2018
  • In [1], the authors generalize the concept of the class group of an integral domain $D(Cl_t(D))$ by introducing the notion of the S-class group of an integral domain where S is a multiplicative subset of D. The S-class group of D, $S-Cl_t(D)$, is the group of fractional t-invertible t-ideals of D under the t-multiplication modulo its subgroup of S-principal t-invertible t-ideals of D. In this paper we study when $S-Cl_t(D){\simeq}S-Cl_t(D_T)$, where T is a multiplicative subset generated by prime elements of D. We show that if D is a Mori domain, T a multiplicative subset generated by prime elements of D and S a multiplicative subset of D, then the natural homomorphism $S-Cl_t(D){\rightarrow}S-Cl_t(D_T)$ is an isomorphism. In particular, we give an S-version of Nagata's Theorem [13]: Let D be a Krull domain, T a multiplicative subset generated by prime elements of D and S another multiplicative subset of D. If $D_T$ is an S-factorial domain, then D is an S-factorial domain.

On the Gauss Map of Tubular Surfaces in Pseudo Galilean 3-Space

  • Tuncer, Yilmaz;Karacan, Murat Kemal;Yoon, Dae Won
    • Kyungpook Mathematical Journal
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    • 제62권3호
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    • pp.497-507
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    • 2022
  • In this study, we define tubular surfaces in Pseudo Galilean 3-space as type-1 or type-2. Using the X(s, t) position vectors of the surfaces and G(s, t) Gaussian transformations, we obtain equations for the two types of tubular surfaces that satisfy the conditions ∆X(s, t) = 0, ∆X(s, t) = AX(s, t), ∆X(s, t) = λX(s, t), ∆X(s, t) = ∆G(s, t), ∆G(s, t) = 0, ∆G(s, t) = AG(s, t) and ∆G(s, t) = λG(s, t).

PSS-PT-PZ 적외선 센서의 초전계수향상에 관한 연구 (A Study on the Improvement of Pyroelectric Coefficient in the PSS-PT-PZ Infrared Sensor)

  • 이성갑;배선기;이영희
    • 대한전기학회논문지
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    • 제41권6호
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    • pp.652-660
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    • 1992
  • 0.10Pb(SbS11/2TSnS11/2T)OS13T-0.25PbTiOS13T-0.65PbZrOS13T ceramics modified by LaS12TOS13T(1[mol%]) and MnOS12T(0-0.30[mol%]) were fabricated. The structural and pyroelectric properties with contents of MnOS12T were studied. Crystal structure of a specimen was rhombohedral type and average grain sizes were decreased with increasing the contents of MnOS12T. Relative dielectric constant and dielectric loss factor were minimum in the specimens doped 0.24[mol%]MnOS12T. (PbS10.99TLaS10.01T)[(SbS11/2TSnS11/2T) TiS10.25TZrS10.65T]OS13T specimen modified 0.24[mol%]MnOS12T showed the good pyroelectric properties and pyroelectric coefficient and voltage responsivity were 6.73x10S0-8T[C/cmS02TK], 125[V/W], respectively. Voltage responsivity was increased with decreasing the chopper frequency.

과학기술인의 종합복지 향상방안 : 과학기술인 종합복지타운 건립을 중심으로 (How to Improve the Welfare of Science & Technology Personnel : Based on the Comprehensive Welfare Town for S&T Personnel)

  • 이종민;임상현;정선양
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 2006년도 제28회 동계학술발표회 논문집
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    • pp.150-169
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    • 2006
  • Science & Technology (S&T) personnel have played a major role to develop our country since S&T is the most important factor to increase national competitiveness in the 21st century. Therefore, it is very essential to increase the welfare of S&T personnel in order to increase national S&T and economic competitiveness. However, the welfare of S&T personnel has not been discussed sufficiently not only in academic research, but also in actual S&T policies. It has caused many. social problems (for example, avoiding fields of S&T of young generation, low social recognition of S&T community and so on). Under this background, this paper aims at investigating how to effectively improve S&T personnel's welfare. For this purpose, we deal with a theoretical review on the welfare of S&T personnel. After that, we will suggest 'Comprehensive Welfare Town for S&T Personnel' as a method of improving the welfare of S&T personnel.

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과학기술관계법제의 정비방안 연구 (A Study on the Reform of Korean S&T Related Law)

  • 송종국;오준근
    • 기술혁신연구
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    • 제2권1호
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    • pp.142-169
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    • 1994
  • Korean Government has established a lot of S&T laws to promote National Science and Technology since established the Ministry of S&T and the S&T Promotion Law in 1967. There are more than ninties of S&T related laws to support Government's S&T policies recently. Even though Korean Government has enacted plenty of S&T related laws are required to be reformed. In this paper, firstly, we define what is S&T related law and the relationship between S&T related law system. Secondly, we investigate the problems of S&T related law with respect to several aspects such as historical, executing, international environment, and systematic aspects. Finally, we suggest the directions of S&T law reform. We conclude that S&T laws need to be merged and abolished in some areas such as various council system and S&T incentive system especially related to UR restriction.

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