• 제목/요약/키워드: tightly bound

검색결과 58건 처리시간 0.03초

상한 융합 변수를 갖는 단선형제약 오목함수 최소화 문제의 해법 (An Algorithm for the Singly Linearly Constrained Concave Minimization Problem with Upper Convergent Bounded Variables)

  • 오세호
    • 한국융합학회논문지
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    • 제7권5호
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    • pp.213-219
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    • 2016
  • 본 논문에서는 한 개의 선형 제약식 하에서 의사결정변수가 상한 값을 갖는 오목 함수 최소화 문제를 다룬다. 제시된 분지 한계 해법은 단체를 분할 단위로 사용하였다. 오목함수를 가장 단단하게 하한추정하는 볼록덮개함수를 단체 상에서 유일하게 구할 수 있기 때문이다. 분지가 일어날 때마다 후보 단체로부터 1 차원 낮은 2 개의 하위 단체들이 생성된다. 이 때 후보 단체에 포함되어 있던 가능해 집합은 각각의 하위 단체로 분할된다. 한계 연산 절차는 선형인 볼록 덮개 함수를 목적 함수로 하는 선형계획법을 부문제로 정의하고 해를 구한다. 부문제의 최적 목적함수 값으로부터 최적 오목목적함수의 하한과 상한을 갱신하고, 원문제의 최적해를 포함하지 않는 단체들을 고려 대상에서 제외시킨다. 본 해법의 최대 장점은 하위 단체로 분할될수록 부문제들의 크기가 점점 작아진다는데 있다. 이것은 한계 연산의 계산량이 줄어든다는 것을 의미한다. 본 연구의 결과는 배낭 제약식 유형의 제약식 하에서의 오목 함수 최소화 문제의 해법을 개발하는데 응용될 수 있을 것이다.

Flocculation of microalgae using extracellular polymeric substances (EPS) extracted from activated sludge

  • Dong, Dandan;Seo, Dongmin;Seo, Sungkyu;Lee, Jae Woo
    • Membrane and Water Treatment
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    • 제9권3호
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    • pp.147-153
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    • 2018
  • This study investigates the role of microbial extracellular polymeric substances (EPSs) as bioflocculants to harvest microalgae (water-microalgae separation). The EPS extracted from waste activated sludge (WAS) by heat extraction were fractionated into soluble EPS (S-EPS), loosely-bound EPS (LB-EPS) and tightly-bound EPS (TB-EPS) forms. All the EPSs facilitated the flocculation of microalgal cells from stable growth medium. Of those EPSs, the TB-EPS showed the highest flocculating activity (FA) resulting in the substantial decrease in the amount of EPS added in terms of total organic carbon (TOC) during flocculation. The FA of microalgae was improved with the increase in TB-EPS dose, however, excessive dose of TB-EPS adversely affected it due to destabilization. Both LB- and TB-EPS could be utilized for flocculating microalgae as a sustainable option to the existing chemical-based flocculants. In addition to the conventional assessments, the effectiveness of the two bioflocculants for floc forming was also confirmed using a novel assessment of lens-free shadow imaging technique (LSIT), which was firstly applied for the rapid and quantitative assessment of microalgal flocculation.

사람 NC-37 세포에서 Benzo(a)pyrene과 Doxorubicin에 의한 Nuclei내전과 c-myc 유전자의 발현에 대한 연구 (Studies on the Nuclei Adduction and Expression of c-myc Gene by Benzo(a)pyrene and Doxorubicin in Human NC-37 Cells)

  • 김호찬;정인철;조무연
    • 생명과학회지
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    • 제8권4호
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    • pp.400-409
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    • 1998
  • Formation of adduct was studied in benzo(a)pyrene(BP)- and doxorubicin(Dx)-treated human NC-37 cells and isolated nuclei. Major adducts formed were determined by fluorescence absorption spectrophotometery and DNA-lin-ked protein assay. When isolated nuclei were exposed to carcinogens BP and DMBA, and anticancer drugs m-AMSA, ellipticine and Dx, varying degrees of adduct formation occured between DNA-protein complex and these drugs. When the mixture was centrifuged 1.7 M sucrose solution, binding BP and DMBA appeared to be similar between the sediment and the supernatant. When the sediment was centrifuged again with 0.35% polymin-P, the amount of BP bound was 2-fold greater in the protein(1077$\pm$55cpm) than in DNA fraction (470$\pm$20cpm), whereas that of DMBA was 1.6-fold greater in the DNA than in protein fraction. In the case of m-AMSA, ellipticine and Dx, the amount of binding was slightly greater in supernatant than in sediment in centrifugation with 1.7 M sucrose, and more than 3 times greater in the DNA- than in protein- fraction in centrifugation with 0.35% polymin P. DNA fractions which associated with a subset of nonhistone chromosomal protein were isolated from NC-37 cells exposed to $^{3}$H-BP and $^{14}$C-Dx. They were separated into two distince components DNA-S and DNA-P by centrifugation with 2M Nacl chromatin extraction. The results indicated that the amount of $^{3}$H-BP bound was 6.0-fold greater in DNA-P as compared with DNA-S, while that of $^{14}$C-Dx binding appreaed to be 6.2-fold greater in DNA-S than in DNA-P fraction. When $^{3}$H-BP binding wasdetermined in the presence of cold Dx, the amount of binding was reduced only in the DNA-P fraction, indicating that the interaction between DNA and protein is decreased. Gene expression by these drugs, BP treated cells were increased to compare with nomal cells but reduced by treatment with BP-Dx. These results suggest that the protein moiety which tightly bound to DNA-P fraction may play an important role in the regulation of gene expression.

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Production of Polyclonal Antibodies against the Tegument of Sparganum (Plerocercoid of Spirometra mansoni) and Its Immunolocalization

  • Yang, Hyun-Jong
    • Parasites, Hosts and Diseases
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    • 제48권2호
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    • pp.183-185
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    • 2010
  • In a previous study, the author developed a method for separation of the tegument of spargana (plerocercoids of Spirometra mansoni) from the parenchyme using urea. The present study, as a next step, was performed to evaluate which molecules are present in the outer tegument. Two major proteins, 180 and 200 kDa, are present in the tegument and we could make polyclonal antibodies against these molecules. Their immunolocalization was processed and the outermost layer of the spargana showed strong positive staining. Conclusively, we could confirm that the 180 and 200 kDa molecules might be tightly bound membrane proteins in the tegument of spargana.

Characterization and function of human Ly-6/uPAR molecules

  • Kong, Hyun Kyung;Park, Jong Hoon
    • BMB Reports
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    • 제45권11호
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    • pp.595-603
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    • 2012
  • Human Ly-6/uPAR molecules are a superfamily composed of two subfamilies; one is the membrane bound proteins with a GPI-anchor and the other are secreted proteins without the GPI-anchor. Ly-6/uPAR molecules have remarkable amino acid homology through a distinctive 8-10 cysteine-rich domain that is associated predominantly with O-linked glycans. These molecules are encoded by multiple tightly linked genes located on Chr. 8q23, and have a conserved genomic organization. Ly-6/uPAR molecules have an interesting expression pattern during hematopoiesis and on specific tumors indicating that Ly-6/uPAR molecules are associated with development of the immune system and carcinogenesis. Thus, Ly-6/uPAR molecules are useful antigens for diagnostic and therapeutic targets. This review summarizes our understanding of human Ly-6/uPAR molecules with regard to molecular structure as well as what is known about their function in normal and malignant tissues and suggest Ly-6/uPAR molecules as target antigens for cancer immunotherapy.

Outage Analysis and Power Allocation for Distributed Space-Time Coding-Based Cooperative Systems over Rayleigh Fading Channels

  • Lee, In-Ho
    • Journal of information and communication convergence engineering
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    • 제15권1호
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    • pp.21-27
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    • 2017
  • In this research, we study the outage probability for distributed space-time coding-based cooperative (DSTC) systems with amplify-and-forward relaying over Rayleigh fading channels with a high temporal correlation where the direct link between the source and the destination is available. In particular, we derive the upper and lower bounds of the outage probability as well as their corresponding asymptotic expressions. In addition, using only the average channel powers for the source-to-relay and relay-to-destination links, we propose an efficient power allocation scheme between the source and the relay to minimize the asymptotic upper bound of the outage probability. Through a numerical investigation, we verify the analytical expressions as well as the effectiveness of the proposed efficient power allocation. The numerical results show that the lower and upper bounds tightly correspond to the exact outage probability, and the proposed efficient power allocation scheme provides an outage probability similar to that of the optimal power allocation scheme that minimizes the exact outage probability.

Cellulosome-Like Structures in Ruminal Cellulolytic Bacterium Ruminococcus albus F-40 as Revealed by Electron Microscopy

  • Kim, Y.S.;Singh, A.P.;Wi, S.G.;Myung, K.H.;Karita, S.;Ohmiya, K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권10호
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    • pp.1429-1433
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    • 2001
  • This study provides electron microscopic evidence for the presence of cellulosome-like structures on the cell surface of Ruminococcus albus F-40. Electron microscopy showed that clusters of tightly packed spherical particles were located on the cell surface of R. albus. The protuberant structures present mainly on the bacterial surface and also bound to the cellulose substrate appeared to be the site of cellulosome-like structures. From the evidence presented, we suggest that the structures described here might be a characteristic feature of some ruminal cellulolytic bacteria.

Purification and Acetylation of Protein X Subunit of Pyruvate Dehydrogenase Complex (PDC) from Bovine Kidney

  • Ryu, Ryu;Song, Byoung-J.;Hong, Sung-Youl;Huh, Jae-Wook
    • Archives of Pharmacal Research
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    • 제19권6호
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    • pp.502-506
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    • 1996
  • Protein X is one of the subunits of pyruvate dehydrogenase complex. The biological role of this protein has not been fully elucidated, mainly because of the difficulty in its dissociation from the tightly bound dihydrolipoamide acetyltransferase-protein X subcomplex. We have found that the detachment of protein X from acetyltransferase subunit can be easily accomplished by the cycles of freezing and thawing proces. Several lines of evidence including sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequence analysis and acetylation with $[2^{14}C]$ pyruvate confirmed that the purified protein is protein X. The purified intact form of protein X was acetylated by $[2^{14}C]$ pyruvate in the presence of py-ruvate dehydrogenase subunit.The acetylation efficiency of this protein was lower than that of acetyltransferase and was not affected by the presence of acetyltransferase.

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Korea's Inflation Expectations with regard to the Phillips Curve and Implications of the COVID-19 Crisis

  • JUNG, KYU-CHUL
    • KDI Journal of Economic Policy
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    • 제43권2호
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    • pp.81-101
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    • 2021
  • This paper estimates the expectation-augmented Phillips curve, which explains inflation dynamics, in Korea. The phenomenon of low inflation in Korea has been going on for quite some time, in particular since 2012. During the Covid-19 crisis, due to low inflation expectations the operation of monetary policy was limited as the base rate approached the zero lower bound. The main objective of this paper is to estimate where and how tightly inflation expectations are anchored. It was found that long-term inflation expectations fell to around 1%, falling short of the inflation target, and that inflation expectations are strongly anchored to long-term expectations, which implies that the low inflation phenomenon is likely to extend into the future. The results also imply that even if inflation fluctuates due to temporary disturbances, it may converge to a level below the inflation target. The slight rebound of long-term expectations during the Covid-19 crisis suggests that the aggressive monetary policy may have contributed to improving economic agents' beliefs about the commitment of monetary authorities to inflation stability. This may also help long-term expectations gradually to approach the inflation target.

Helical Rim Advancement Flap with an Additional Postauricular Skin Flap: A Case Report

  • Kim, Seung Ho;Choi, Jeong Hwan
    • 대한청각학회지
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    • 제23권4호
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    • pp.210-213
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    • 2019
  • The auricle is a three-dimensional cartilaginous frame covered with thin overlying skin. Due to its complex features, reconstructing helical rim defects after the excision of an auricular mass is challenging. Shortage of subcutaneous tissue and the presence of a tightly bound epithelium further hamper the primary closure of lateral (anterior) auricular skin defects. We present herein a case in which we used a helical rim advancement flap along with an additional postauricular skin flap. We achieved a satisfactory esthetic result with minimal loss of helical diameter and a low risk of flap necrosis by preserving the vascular network of the flap. This technique is less traumatic and will facilitate faster healing as well as improved patient recovery.