• 제목/요약/키워드: B56

검색결과 2,527건 처리시간 0.024초

한라산국립공원의 조류군집에 관한 연구 (A Study on the Bird Community in Hallasan National Park)

  • 전병선;유재평;백인환;오홍식;백운기
    • 한국환경생태학회지
    • /
    • 제21권2호
    • /
    • pp.149-160
    • /
    • 2007
  • 한라산국립공원의 조사지역에서 2006년 4월부터 2007년 2월까지 3차례에 걸쳐 조사한 결과 관찰된 조류는 38종 2,323개체였다. 이 중 텃새가 27종이었고, 여름철새가 6종, 겨울철새가 2종, 통과새가 3종이었다. 최우점종은 큰부리까마귀(14.81%)였으며, 다음은 직박구리(12.66%), 방울새(10.33%), 까마귀(8.44%), 곤줄박이(6.72%) 등의 순이었다. 산록도로지 역(A지역)에서는 31종 1,630개체의 조류가 관찰되었고, 탐방로지역(B지역)의 27종 693개체 보다 많은 것으로 나타났다 종다양도(H')는 $1.34{\sim}2.56$의 범위에서 봄 조사시 A지 역에서 종다양도 2.56으로 가장 높았고. 겨울 조사시 B지역에서 1.34로 가장 낮았다. 고도별로 각 종들의 분포양상이 다르게 나타난 것은 고도에 따른 기상요건과 먹이원의 차이에 의한 것으로 보인다.

UNICITY OF MERMORPHIC FUNCTIONS CONCERNING SHARED FUNCTIONS WITH THEIR DIFFERENCE

  • Deng, Bingmao;Fang, Mingliang;Liu, Dan
    • 대한수학회보
    • /
    • 제56권6호
    • /
    • pp.1511-1524
    • /
    • 2019
  • In this paper, we investigate the uniqueness of meromorphic functions of finite order concerning sharing small functions and prove that if f(z) and ${\Delta}_cf(z)$ share a(z), b(z), ${\infty}$ CM, where a(z), b(z)(${\neq}{\infty}$) are two distinct small functions of f(z), then $f(z){\equiv}{\Delta}_cf(z)$. The result improves the results due to Li et al. ([9]), Cui et al. ([1]) and $L{\ddot{u}}$ et al. ([12]).

WEAKLY PRIME IDEALS IN COMMUTATIVE SEMIGROUPS

  • Anderson, D.D.;Chun, Sangmin;Juett, Jason R.
    • 대한수학회보
    • /
    • 제56권4호
    • /
    • pp.829-839
    • /
    • 2019
  • Let S be a commutative semigroup with 0 and 1. A proper ideal P of S is weakly prime if for $a,\;b{\in}S$, $0{\neq}ab{\in}P$ implies $a{\in}P$ or $b{\in}P$. We investigate weakly prime ideals and related ideals of S. We also relate weakly prime principal ideals to unique factorization in commutative semigroups.

ON CONGRUENCES INVOLVING THE GENERALIZED CATALAN NUMBERS AND HARMONIC NUMBERS

  • Koparal, Sibel;Omur, Nese
    • 대한수학회보
    • /
    • 제56권3호
    • /
    • pp.649-658
    • /
    • 2019
  • In this paper, we prove some congruences involving the generalized Catalan numbers and harmonic numbers modulo $p^2$, one of which is $$\sum\limits_{k=1}^{p-1}k^2B_{p,k}B_{p,k-d}{\equiv}4(-1)^d\{{\frac{1}{3}}d(2d^2+1)(4pH_d-1)-p\({\frac{26}{9}}d^3+{\frac{4}{3}}d^2+{\frac{7}{9}}d+{\frac{1}{2}}\)\}\;(mod\;p^2)$$, where a prime number p > 3 and $1{\leq}d{\leq}p$.

Degradation of Chlorinated Organic Compounds by Zero Valent Metals and an Electron carrier

  • Kim, Young-Hun
    • 한국지하수토양환경학회:학술대회논문집
    • /
    • 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
    • /
    • pp.53-56
    • /
    • 2001
  • The degradation of tetrachloroethene (PCE) and trichloroethene (TCE) by vitamin B$_{12}$, an electron mediator was examined when zero valent metals (ZVMs) were used as built electron donors. Dechlorination of PCE and TCE by iron and zinc in the presence of vitamin B$_{12}$ showed that the zinc and vitamin B$_{12}$ combination greatly enhances the reaction rates for both PCE and TCE, but iron and vitamin B$_{12}$ result in an increase in reactivity only for PCE degradation, not for TCE degradation in comparing with meta]s only. This result indicates vitamin B$_{12}$(I) Is active towards both PCE and TCE degradation while vitamin B$_{12}$(II) is active towards both PCE. Calculated activation energies for the dechlorination of PCE in the presence of Vitamin B$_{12}$ showed that vitamin B$_{12}$ lowered the activation energy about 40-60 kJ/㏖ for the both metals.the both metals.

  • PDF

Bithyniidae과 (중복족목) 패류 8종의 패각과 뚜껑의 형태 관찰 (Morphological Observations on Shells and Operculums of Eight Bithyniids)

  • 김재진
    • 한국패류학회지
    • /
    • 제5권1호
    • /
    • pp.42-56
    • /
    • 1989
  • Shells and operculums of eight species of Bithyniidae, Bithynia leachi, B. tentaculata, B. siamensis, B. misella, B. kiusiuensis, Gabbia australis, B. manchourica and a Bithynia sp. collected from Nepal, were observed, There is no morphological difference between korean populations of B. misella and a Japanese popualtion of B. kiusiuensis. And the shells of these species were simialr to the other Bithynia species rather than Australian Gabbia. The coordinate of the starting point of nuclear spire of operculum(SPN)was species specific and this value had very limited range within a species. The result suggested that Korean and Japanese populations of B. misella and B. kiusiuensis are synonym and the coordinate of SPN will be a useful character in sytematics of operculated snails.

  • PDF

Conformation and Biological Activity of Mastoparan B and Its Analogs I

  • 박남규;서정길;구희정;이산나무;Gohsuke Sugihara;김광호;박장수;강신원
    • Bulletin of the Korean Chemical Society
    • /
    • 제18권1호
    • /
    • pp.50-56
    • /
    • 1997
  • The mode of action of mastoparan B, an antimicrobial cationic tetradecapeptide amide isolated from the hornet Vespa basalis, toward phospholipid bilayers was studied with synthetic mastoparan B and its analogs with individual Ala instead of hydrophobic amino acids (1-Ile, 3-Leu, 6-Leu, 7-Val, 9-Trp, 13-Val, 14-Leu) in mastoparan B. Mastoparan B and its analogs were synthesized by the solid-phase method. Circular dichroism spectra showed that mastoparan B and its analogs adopted an unordered structure in buffer solution. In the presence of neutral and acidic liposomes, most of the peptides took an α-helical structure. The calcein leakage experiment indicated that mastoparan B interacted strongly with neutral and acidic lipid bilayers than its analogs. Mastoparan B also showed a more or less highly antimicrobial activity and hemolytic activity for human erythrocytes than its analogs. These results indicate that the hydrophobic face in the amphipathic α-helix of mastoparan B critically affect biological activity and helical contents.

THE NUMBER OF REPRESENTATIONS OF A POSITIVE INTEGER BY TRIANGULAR, SQUARE AND DECAGONAL NUMBERS

  • Isnaini, Uha;Melham, Ray;Toh, Pee Choon
    • 대한수학회보
    • /
    • 제56권5호
    • /
    • pp.1143-1157
    • /
    • 2019
  • Let $T_aD_b(n)$ and $T_aD^{\prime}_b(n)$ denote respectively the number of representations of a positive integer n by $a(x^2-x)/2+b(4y^2-3y)$ and $a(x^2-x)/2+b(4y^2-y)$. Similarly, let $S_aD_b(n)$ and $S_aD^{\prime}_b(n)$ denote respectively the number of representations of n by $ax^2+b(4y^2-3y)$ and $ax^2+b(4y^2-y)$. In this paper, we prove 162 formulas for these functions.

Chronology and environment of the Palaeolithic and Neolithic cultures on the southern Russian Far East

  • Kuzmin, Yaroslav V.
    • 한국제4기학회지
    • /
    • 제16권2호
    • /
    • pp.39-56
    • /
    • 2002
  • The results of geoarchaeological studies of the prehistoric cultural complexes on the Russian Far East (Primorye, or Maritime Province; the Amur River basin; and Sakhalin Island) are presented. Upper Palaeolithic sites are dated to ca. 40,000-10,500 B.P. They existed during the mild climate of the Chernoruchie interstadial (ca. 40,000-21,000 B.P.); during harsh climate at the Last Glacial Maximum, ca. 20,000-18,000 B.P., in several places on the Russian Far East (Primorye, Amur River basin, and Sakhalin); and during climatic amelioration in the Late Glacial time, ca. 16,000-10,500 B.P. The earliest Neolithic sites, represented by Osipovka and Gromatukha cultures, existed at ca. 13,000-10,000 B.P. in the environment of coniferous forests with admixture of broadleaved taxa. Since ca. 8000 B.P., Neolithic cultures appeared in all of the Russian Far East. They existed until ca. 3000 B.P., first during the Holocene Climatic Optimum, ca. 8000-5000 B.P., in the environment of coniferous-broadleaved forests, and later, at ca. 5000-3000 B.P., in the environment of birch-oak and coniferous forests.

  • PDF

전자기기의 전원 노이즈 저감을 위한 EMI 필터 경험적 설계에 관한 연구 (A study on the Empirical Design of EMI Filters for Power Supply Noise Reduction in Electronic Devices)

  • 이윤민;신진섭
    • 한국인터넷방송통신학회논문지
    • /
    • 제23권4호
    • /
    • pp.59-64
    • /
    • 2023
  • 본 논문은 전자기기에 사용되는 전원의 노이즈 저감을 위한 전도성(Conducted) EMI 필터의 경험적 설계를 통하여 제안하였다. 제안된 구조는 A형, B형, C형, D형의 구조를 설계하였으며, 다양한 X-커패스터와, Y-커패스터, Air-인덕터로 LC 네트워크 사용으로 전도성 노이즈 저감을 확인하였다. L1, L2는 10[μH]를 사용하였으며, C1, C2는 4.7[nF]를 사용하였다. 공통모드(Common Mode)용 L3는 13[μH]를 사용하였으며, C5, C6, C7은 10[nF]을 사용하여 설계하였다. 설계된 EMI 필터의 측정된 삽입손실 값은 3.2MHz에서 -74.4[dB], 4MHz에서 -75.4[dB], 13.56MHz에서 -75.3[dB]로 나타났다. 따라서 제안한 EMI 필터는 다양한 전자기기에 사용되는 전원 노이즈 저감에 이용될 것이다.