• 제목/요약/키워드: condition number

검색결과 5,614건 처리시간 0.031초

운전중인 대형 터빈발전기에서 절연상태 평가 (Assessment of Insulation Condition in Operating Large Turbine Generator)

  • 김희동
    • 대한전기학회논문지:전기물성ㆍ응용부문C
    • /
    • 제53권6호
    • /
    • pp.324-329
    • /
    • 2004
  • Six stator slot couplers(SSC) and a flux probe sensor installed on the stator winding slots of large turbine generator. Assessment of insulation condition has been based upon the measurements of partial discharge(PD) of stator windings and shorted-turn of rotor windings in operating large turbine generator. The maximum PD magnitude(Qm), normalized quantify number(NQN), PD pattern and shorted-turn were measured using on-line insulation condition monitoring system. The NQN and Qm of slot PD side in the phase A are indicated the highest value in six SSC sensors. Monitoring system results showed that discharge at conductor surface and internal discharge were detected at the surface of stator winding and in voids of the groundwall insulation. Insulation of stator and rotor windings in large turbine generator was judged to be in good condition.

RICCI CURVATURE, CIRCULANTS, AND EXTENDED MATCHING CONDITIONS

  • Dagli, Mehmet;Olmez, Oktay;Smith, Jonathan D.H.
    • 대한수학회보
    • /
    • 제56권1호
    • /
    • pp.201-217
    • /
    • 2019
  • Ricci curvature for locally finite graphs, as proposed by Lin, Lu and Yau, provides a useful isomorphism invariant. A Matching Condition was introduced as a key tool for computation of this Ricci curvature. The scope of the Matching Condition is quite broad, but it does not cover all cases. Thus the current paper introduces extended versions of the Matching Condition, and applies them to the computation of the Ricci curvature of a class of circulants determined by certain number-theoretic data. The classical Matching Condition is also applied to determine the Ricci curvature for other families of circulants, along with Cayley graphs of abelian groups that are generated by the complements of (unions of) subgroups.

Varietal Variation in Biomass Production and Total Digestible Nutrients of Maize Grown under Lowland Condition

  • Youngchul Yoo;Dae-Woo Lee
    • 한국작물학회:학술대회논문집
    • /
    • 한국작물학회 2022년도 추계학술대회
    • /
    • pp.99-99
    • /
    • 2022
  • This study was carried out to select the excellent silage maize varieties customized for paddy cultivation that is vulnerable to lodging and waterlogging in the central and region. Ten varieties (Kwangpyeongok, P3394, etc.) were sown with 3 replicates in Suwon, Gyeonggi-do. It was sown twice in April and June of each year in 2020-2021 and harvested during the yellow ripe stage suitable for silage. The number of days to flowering stage in lowland condition increased up to 11 days compared to that in upland condition. In April seedling, varieties that showed a relatively small decrease in biomass production and total digestible nutrients (TDN) under lowland condition compared to upland condition were Gangdaok and Kwangpyeongok in 2020, and Dacheongok, Gangdaok and Kwangpyeongok in 2021. Kwangpyeongok, Gangdaok, and Sinhwangok showed relatively higher biomass production and TDN than the other varieties under lowland compared to upland in both 2020 and 2021. Our results suggest that Kwangpyeongok and Gangdaok are suitable silage maize varieties for lowland cultivation in the central region of Korea.

  • PDF

A Concept on Seat Assignment Systems

  • Premasathian, Nol;Tantipisankul, Tasanee;Sinapiromsaran, Charoen
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2003년도 ICCAS
    • /
    • pp.458-461
    • /
    • 2003
  • This paper presents a concept on seat assignment systems. The concept is based on the assumption that customers or passengers prefer to select seats at their own choosing and allowing them to do so would fragment remaining seats. This undesirable condition may make a group of people intending to be seated together unable to find a sufficient number of consecutive seats. The concept proposed is to set aside a number of seats when the map of available seats is shown for customer's selection. A number of functions are created to allot seats to be visible for choosing according to the number and locations of the remaining seats and the number in the group of the passengers. Passengers' preferences such as window or aisle seating, front seating are taken into accounts. A primitive example of seat assignment system of a Boeing 717 aircraft, assuming the number of passengers in a group being 1, 2 or 3, is given based on the concept.

  • PDF

열적 비대칭 삼각 핀의 열전달 해석; 핀 끝 효과에 기준 (A Heat Transfer Analysis of a Thermally Asymmetric Triangular Fin; Based on Fin Tip Effect)

  • 강형석
    • 산업기술연구
    • /
    • 제22권B호
    • /
    • pp.21-26
    • /
    • 2002
  • The non-dimensional heat loss from a thermally asymmetric triangular fin is investigated as a function of a ratio of upper and lower surface Biot numbers (Bi2/Bi1), the non-dimensional fin length and tip surface Biot number using the two-dimensional separation of variables method. The effect of fin tip surface Biot number on the variation of the non-dimensional temperature along the sloped upper and lower surfaces for the thermally asymmetric condition is presented. The relationship between the non-dimensional fin length and the fin tip surface Biot number for equal amount of heat loss is also discussed as well as the relationship between upper surface Biot number and tip surface Biot number for equal amount of heat loss.

  • PDF

열적 비대칭 삼각 휜의 성능해석 (Performance Analysis of a Thermally Asymmetric Triangular Fin)

  • 강형석
    • 대한기계학회논문집B
    • /
    • 제26권1호
    • /
    • pp.66-73
    • /
    • 2002
  • Fin effectiveness and efficiency of a thermally asymmetric triangular fin are represented as a function of the ratio of fin lower surface Biot number to upper surface Biot number and the non-dimensional fin length. For this analysis, two dimensional separation of variables method is used. When fin effectiveness is 2 and efficiency is 90%, the relationship between the non-dimensional fin length and the ratio of fin lower stir(ace Biot number to upper surface Biot number is shown. The relationship between the non-dimensional fin length and the upper surface Biot number for the same condition is also presented.

유과 조리법의 표준화에 관한 연구(I) -찹쌀의 수침기간과 꽈리치기 횟수를 중심으로- (Studies on Optimum Conditions for Experimental Procedure of Yukwa (I) -On the soaking time of glutuous rice and the number of beating-)

  • 전형주;손경희;박현경
    • 한국식생활문화학회지
    • /
    • 제10권2호
    • /
    • pp.75-81
    • /
    • 1995
  • This study was attempted to standard Yukwa recipies by proposing optimal conditions for soaking time and the number of beating. Soaking time and the number of beating had effects on the number of peak, implying that 15 days of soaking time at $15^{\circ}C$ and 160 times of beating would be required. In Yukwa's microstructural image, the better groups were over 15 days of soaking time and as number of beating increased, the appearance improved. The longer soaking time, the better tenderness and expansion volume. The number of beating had significant effects on all sensory evaluation except volume. Response surface model showed that the optimal condition would be at least 15 days of soaking and 319 times of beating.

  • PDF

Recognition of Car License Plate using Kohonen Algorithm

  • Lim, Eun-Kyoung;Yang, Hwang-Kyu;Kwang Baek kim
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 ITC-CSCC -2
    • /
    • pp.785-788
    • /
    • 2000
  • The recognition system of a car plate is largely classified as the extraction and recognition of number plate. In this paper, we extract the number plate domain by using a thresholding method as a preprocess step. The computation of the density in a given mask provides a clue of a candidate domain whose density ratio corresponds to the properties of the number plate obtained in the best condition. The contour of the number plate for the recognition of the texts of number plate is extracted by operating Kohonen Algorithm in a localized region. The algorithm reduces noises around the contour. The recognition system with the density computation and Kohonen Algorithm shows a high performance in the real system in connection with a car number plate.

  • PDF

GRAPHS WITH ONE HOLE AND COMPETITION NUMBER ONE

  • KIM SUH-RYUNG
    • 대한수학회지
    • /
    • 제42권6호
    • /
    • pp.1251-1264
    • /
    • 2005
  • Let D be an acyclic digraph. The competition graph of D has the same set of vertices as D and an edge between vertices u and v if and only if there is a vertex x in D such that (u, x) and (v, x) are arcs of D. The competition number of a graph G, denoted by k(G), is the smallest number k such that G together with k isolated vertices is the competition graph of an acyclic digraph. It is known to be difficult to compute the competition number of a graph in general. Even characterizing the graphs with competition number one looks hard. In this paper, we continue the work done by Cho and Kim[3] to characterize the graphs with one hole and competition number one. We give a sufficient condition for a graph with one hole to have competition number one. This generates a huge class of graphs with one hole and competition number one. Then we completely characterize the graphs with one hole and competition number one that do not have a vertex adjacent to all the vertices of the hole. Also we show that deleting pendant vertices from a connected graph does not change the competition number of the original graph as long as the resulting graph is not trivial, and this allows us to construct infinitely many graph having the same competition number. Finally we pose an interesting open problem.

대입수험생의 식사행동이 그들의 건강상태에 미치는 영향 (Influence of Entrance Examinees' Eating Behavior on their Health Condition.)

  • 조진숙;김기남
    • 한국생활과학회지
    • /
    • 제2권1호
    • /
    • pp.25-31
    • /
    • 1993
  • The purpose of this study was to find out the influence of Entrance Examinees' Eating Behavior on their health condition. The examinees for Chungbuk National university in 1992 were asked to fill out the questionnaire(The total number was 1054 ; 537 males, 517 females). The statistics used for data analysis were frequency, percentage, Crosstabs, Chi-square, t-test, one-way Anova, and Multiple Regression using SPSS/PC+ Program. The results are as follows. 1. Health condition due to an eating attitude: 1) As to health condition due to the food intake freguency, those who intaked fish or meat 3-5 days a week had the best heal th condition, but those who hardly intaked fish and meat or intaked them almost everyday had rather poor health condition. Those who intaked fried foods 1-2 days a week had the best health condition. The higher the freguency intaking such food or instant food was, the worse health condition was. 2) In view of health condition according to an eating attitude, it led to very good health condition to have breakfast & supper, to eat regularly, to select the nutritious foods, and to have a balanced diet. Overeating before sleeping and no meal or overeating before exam made their health very bad. Alcohol drinking & cigarrette smoking as favorite foods appeared significantly high in the boys. The more frequently they drinked alcohol and smoked cigarrette the worse their health condition was. Those who enjoyed milk, soya milk, and korean tea as favorite beverages had the better health condition than those who enjoyed coffee and soft drinks. 2. Influence of Eating Behavior on Health Condition. 1) The food intake freguency and the eating attitude influenced each other. The higher the score of food intake frequency was, the better the eating attitude appeared. 2) As a result of this study for eating behavior influencing on their health condition, the eating attitude influenced health condition, and the higher the eating attitude score was, the better heal th condition could be.

  • PDF