• 제목/요약/키워드: Positive linear maps

검색결과 9건 처리시간 0.023초

BOUNDARIES OF THE CONE OF POSITIVE LINEAR MAPS AND ITS SUBCONES IN MATRIX ALGEBRAS

  • Kye, Seung-Hyeok
    • 대한수학회지
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    • 제33권3호
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    • pp.669-677
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    • 1996
  • Let $M_n$ be the $C^*$-algebra of all $n \times n$ matrices over the complex field, and $P[M_m, M_n]$ the convex cone of all positive linear maps from $M_m$ into $M_n$ that is, the maps which send the set of positive semidefinite matrices in $M_m$ into the set of positive semi-definite matrices in $M_n$. The convex structures of $P[M_m, M_n]$ are highly complicated even in low dimensions, and several authors [CL, KK, LW, O, R, S, W]have considered the possibility of decomposition of $P[M_m, M_n] into subcones.

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INTERSECTIONS OF MAXIMAL FACES IN THE CONVEX SET OF POSITIVE LINEAR MAPS BETWEEN MATRIX ALGEBRAS

  • Kye, Seung-Hyeok;Lee, Sa-Ge
    • 대한수학회논문집
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    • 제10권4호
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    • pp.917-924
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    • 1995
  • Let $P_I$ be the convex compact set of all unital positive linear maps between the $n \times n$ matrix algebra over the complex field. We find a necessary and sufficient condition for which two maximal faces of $\cap P_I$ intersect. In particular, we show that any pair of maximal faces of $P_I$ has the nonempty intersection, whenever $n \geq 3$.

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The Linear Discrepancy of a Fuzzy Poset

  • Cheong, Min-Seok;Chae, Gab-Byung;Kim, Sang-Mok
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제11권1호
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    • pp.59-64
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    • 2011
  • In 2001, the notion of a fuzzy poset defined on a set X via a triplet (L, G, I) of functions with domain X ${\times}$ X and range [0, 1] satisfying a special condition L+G+I = 1 is introduced by J. Negger and Hee Sik Kim, where L is the 'less than' function, G is the 'greater than' function, and I is the 'incomparable to' function. Using this approach, we are able to define a special class of fuzzy posets, and define the 'skeleton' of a fuzzy poset in view of major relation. In this sense, we define the linear discrepancy of a fuzzy poset of size n as the minimum value of all maximum of I(x, y)${\mid}$f(x)-f(y)${\mid}$ for f ${\in}$ F and x, y ${\in}$ X with I(x, y) > $\frac{1}{2}$, where F is the set of all injective order-preserving maps from the fuzzy poset to the set of positive integers. We first show that the definition is well-defined. Then, it is shown that the optimality appears at the same injective order-preserving maps in both cases of a fuzzy poset and its skeleton if the linear discrepancy of a skeleton of a fuzzy poset is 1.

다문화 청소년의 자아존중감 변화에 영향을 미치는 요인: 선형혼합모형을 활용하여 (Factors Influencing Self-esteem Changes in Multicultural Adolescents: Using a Linear Mixed Model)

  • 서지영;박민아;한명희
    • 지역사회간호학회지
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    • 제33권3호
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    • pp.290-298
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    • 2022
  • Purpose: This study was conducted to determine factors influencing changes in the self-esteem of multicultural adolescents over time. Methods: A longitudinal design was adopted to analyze secondary data. This study used the 2nd, 4th, and 6th year data of Multicultural Adolescents Panel Study (MAPS) collected by the Korea Youth Policy Institute. The linear mixed model was utilized to analyze self-esteem changes over time. Results: The factors of sex and age of the students, the mother's Korean writing ability, and the Filipino or Japanese mothers had a significant effect on the self-esteem change of multi-cultural adolescents over time. Specifically, it was found that female students' self-esteem was decreased by 0.04 (t=-2.39, p=.017) more than male students over time. As the subject's age and mother's Korean writing ability increased, self-esteem was decreased by 0.01 (t=-2.53, p=.011) and 0.03 (t=-2.52, p=.012) over time. In addition, compared to that of those who had mothers from Korea, self-esteem of those who had Filipino or Japanese mothers was decreased by 0.04 significantly. Conclusion: Therefore, when developing a self-esteem promotion program, it is necessary to develop content by reflecting the characteristics of mothers as well as the gender and age of students. Furthermore, the significance of this study is in that it established a foundation for a positive self-identity of multicultural adolescents whose number is increasing recently by identifying factors affecting their self-esteem.

교통조사부문 드론 활용시 비용절감효과 분석 연구 (A Study on Cost Reduction Effect of Drone Implementation in Traffic Survey)

  • 김동준;안효섭;김진태
    • 한국도로학회논문집
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    • 제20권4호
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    • pp.73-84
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    • 2018
  • PURPOSES : Most of the traffic surveys are carried out by an inspection method by the manpower. In some cases, the video equipment is used only in some regions when the traffic volume is surveyed. In this case, there is environmental restriction that the road equipment to fix the video equipment should exist. Also, in areas where information such as digital maps and satellite photographs is old or not provided, they are forced to rely on manpower research, but it is difficult to put huge amounts of time and money into the research in places where labor supply and demand is difficult. This difficulty is particularly pronounced in overseas business. METHODS : The purpose of this study is to improve the efficiency of business by using the drones in the traffic investigation through analysis of the cost reduction effect between the existing method and the proposed method in the overseas business traffic survey. The scope of the research is limited to the scope of research, and based on the case of overseas projects, the method of using drone for each research sector is suggested. RESULTS : In the traffic condition survey section, we propose the use of drone for traffic survey and queue length survey, and it is confirmed that there is a cost saving effect of 16% ~ 27% compared with the existing method. In the road condition survey, we propose the use of drones for road surface linear survey, geometry survey, and obstacle survey, and it was confirmed that the cost reduction effect is 39% ~ 93% compared to the existing method. CONCLUSIONS : In addition to overseas business, it is expected that it will have a positive effect on research time and cost reduction by using drone in traffic survey in domestic area where labor supply is not easy or basic data is insufficient.

신도시 물순환체계 구축을 위한 습지조성 입지선정에 관한 연구 (Site Selection Model for Wetland Restoration and Creation for the Circulation of Water in a Newly-built Community)

  • 최희선;김귀곤
    • 한국조경학회지
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    • 제36권6호
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    • pp.43-54
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    • 2009
  • 본 연구는 새롭게 조성되는 도시의 물순환체계를 구축하고, 도시화로 말미암아 증가하는 유출량을 분산 저류함은 물론, 생물다양성을 증진시킬 수 있는 습지의 조성입지와 면적을 확보하는 것에 중점을 두었다. 습지조성 입지선정을 위하여 유역분석에서부터 평가항목 선정, 가중치 산출, 주제도 작성, 종합 등 일련의 과정을 모형으로 정립하였다. 개발된 모형은 수도권에 입지해 있는 위례 신도시 개발예정지역에 적용함으로써 모형의 실행가능성과 한계를 검토하였다. 적용 결과, 유역분석단계 에서는 대상지가 13개의 소유역으로 구분되며, 개발대상지가 포함되는 유역들의 유입량은 $3,020,765m^3$인 것으로 나타났다. 개발 전 후의 유출량을 비교하면 각각 $1,901,969m^3$, $1,970,735{\sim}2,039,502m^3$로써 개발지역에서 확보해야 할 총 저류량은 $68,766{\sim}137,533m^3$로 산출되었다. 습지조성 입지선정단계에서는 각각의 주제도를 중첩한 결과, 13개 소유역별로 습지조성 우선지역이 차등적으로 분류되었다. 유출량을 저류할 수 있는 습지의 입지와 면적을 도출한 결과, 저류형 습지와 하천형 습지, 연못형 습지 등 다양한 유형의 습지조성은 물론 이들의 유기적 연계가 가능한 것으로 판단되었다. 이는 도시 전체의 물순환체계 계획의 기본골격을 제공함으로써 녹지공간과의 통합을 통해 도시생태 네트워크 계획 수립과 같은 공간계획단계에 유용하게 활용될 수 있을 것으로 판단되었다. 그러나 본 연구는 토지이용계획 이전 단계에서 도시화로 인해 예상되는 잠재적인 유출량을 기준으로 습지의 입지와 면적을 산정함에 따라 정확한 저류량의 산정을 위해서는 토지이용계획 이후 환류(feedback)과정이 요구되었으며, 습지의 유형이나 입지적 특성에 따라서 저류량 등 저류능력이 달라질 수 있음에도 불구하고 문헌에서 고찰되는 일반적인 습지 저류량을 모든 습지에 동일하게 적용했다는 점은 본 연구의 한계라 할 수 있다.