The partitioned-layer index: Answering monotone top-k queries using the convex skyline and partitioning-merging technique

Heo, J.S.,Whang, K.Y.,Kim, M.S.,Kim, Y.R.,Song, I.Y. North-Holland [etc ; Elsevier Science Ltd 2009 Information sciences Vol.179 No.19

A top-k query returns k tuples with the highest (or the lowest) scores from a relation. The score is computed by combining the values of one or more attributes. We focus on top-k queries having monotone linear score functions. Layer-based methods are well-known techniques for top-k query processing. These methods construct a database as a single list of layers. Here, the ith layer has the tuples that can be the top-i tuple. Thus, these methods answer top-k queries by reading at most k layers. Query performance, however, is poor when the number of tuples in each layer (simply, the layer size) is large. In this paper, we propose a new layer-ordering method, called the Partitioned-Layer Index (simply, the PL Index), that significantly improves query performance by reducing the layer size. The PL Index uses the notion of partitioning, which constructs a database as multiple sublayer lists instead of a single layer list subsequently reducing the layer size. The PL Index also uses the convex skyline, which is a subset of the skyline, to construct a sublayer to further reduce the layer size. The PL Index has the following desired properties. The query performance of the PL Index is quite insensitive to the weights of attributes (called the preference vector) of the score function and is approximately linear in the value of k. The PL Index is capable of tuning query performance for the most frequently used value of k by controlling the number of sublayer lists. Experimental results using synthetic and real data sets show that the query performance of the PL Index significantly outperforms existing methods except for small values of k (say, k=<9).

Cooperative Activation of PI3K by Ras and Rho Family Small GTPases

Yang, H.,Shin, M.G.,Lee, S.,Kim, J.R.,Park, W.,Cho, K.H.,Meyer, T.,Do Heo, W. Cell Press 2012 Molecular cell Vol.47 No.2

Phosphoinositide 3-kinases (PI3Ks) and Ras and Rho family small GTPases are key regulators of cell polarization, motility, and chemotaxis. They influence each other's activities by direct and indirect feedback processes that are only partially understood. Here, we show that 21 small GTPase homologs activate PI3K. Using a microscopy-based binding assay, we show that K-Ras, H-Ras, and five homologous Ras family small GTPases function upstream of PI3K by directly binding the PI3K catalytic subunit, p110. In contrast, several Rho family small GTPases activated PI3K by an indirect cooperative positive feedback that required a combination of Rac, CDC42, and RhoG small GTPase activities. Thus, a distributed network of Ras and Rho family small GTPases induces and reinforces PI3K activity, explaining past challenges to elucidate the specific relevance of different small GTPases in regulating PI3K and controlling cell polarization and chemotaxis.

Effect of Different Spray Dried Plasmas on Growth, Ileal Digestibility, Nutrient Deposition, Immunity and Health of Early-Weaned Pigs Challenged with E. coli K88

Bosi, P.,Han, In K.,Jung, H.J.,Heo, K.N.,Perini, S.,Castellazzi, A.M.,Casini, L.,Creston, D.,Gremokolini, C. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.8

A total of 96 piglets were weaned at 19 and 13 days in Exp. 1 and 2, respectively, and allotted to one of four diets: three with different spray dried plasmas (SPs) and one with hydrolysed casein (HC). SPs were from pigs (SPP), mixed origin (SMP), and mixed origin with standardized level of immunoglobulins (SMPIG). All the diets contained 1.7% total lysine, 25% of the test protein source, 45% corn starch, 15% lactose, 2% sucrose, 7% soybean oil. At d 4 and d 2 in Exp. 1 and 2, respectively, piglets were perorally challenged with $10^{10}$ CFU E. coli K88. Growth performance, immunity, and health condition were measured for 15 days and 14 days in Exp. 1 and 2, respectively. To investigate apparent ileal digestibility and nutrient deposition, all piglets were sacrificed at d 14 in Exp. 2. In 1. 3 piglets died in HC diet and 1 in SPP diet. HC diet showed higher mortality (p<0.01) than other diets. In Exp. 2, no clinical sign of infection was detected, no difference for the content of E. coli K88 was found in feces at 4 and 6 days after the infection, and no E. coli K88 was found in the jejunum at the end of experiment. In both experiments, feed intake was lower for HC diet and ADG was 96, 106, 122 and 155 for HC, SPP, SMP and SMPIG diet, respectively (HC vs others, p<0.05; SMPIG vs other SP, p<0.01). Heal apparent digestibility of nitrogen in sacrificed piglets was higher for HC diet (p<0.05). After the challenge, K88-specific titers in saliva (Exp. 1) and in plasma (Exp. 2) were reduced in SMP and SMPIG. The piglets positive to the adhesion of the used E. coli strain to the intestinal brush borders had a significantly reduced growth (p<0.01) and a higher K88-specific IgA titer in plasma, in comparison with negative ones. This effect was independent of the diet. The data show the relevance of spray dried plasma sources and particularly of SP with standardized level of immunoglobulins for the feeding of early-weaned at the risk of infection by enterotoxigenic bacteria.

Simultaneous integration of multiple genes into the Kluyveromyces marxianus chromosome

Heo, P.,Yang, T.J.,Chung, S.C.,Cheon, Y.,Kim, J.S.,Park, J.B.,Koo, H.M.,Cho, K.M.,Seo, J.H.,Park, J.C.,Kweon, D.H. Elsevier Science Publishers 2013 Journal of biotechnology Vol.167 No.3

While Kluyveromyces marxianus is a promising yeast strain for biotechnological applications, genetic engineering of this strain is still challenging, especially when multiple genes are to be transformed. Sequential gene integration, which takes advantage of repetitive insertion/excision of the URA3 gene as a marker, has been the best option until now, because the URA3-deletion mutant is the only precondition for this method. However, we found that the introduced gene is co-excised during the URA3 excision step for next gene introduction, resulting in a very low cumulative probability (<1.57x10<SUP>-6</SUP>% for 4 genes) of integrating all genes of interest. To overcome this extremely low probability, and to reduce labor and time, all 4 genes were simultaneously transformed. Surprisingly, the infamously high 'non-homologous end joining' activity of K. marxianus enabled simultaneous integration of all 4 genes in a single step, with a probability of 7.9%. Various K. marxianus strains could also be similarly transformed. Our finding not only reduces the labor and time required for such procedures, but also removes a number of preconditions, such as pre-made vectors, selection markers and knockout mutants, which are needed to introduce many genes into K. marxianus.

자유드로잉 제품과 패드를 설치한 드로잉 제품의 특성

고관영,명노훈,하종성,이창수,최창권,최병용,허기영,김광수,김동수,장종훈,장윤철,김세환,오정민,하민정,박향자 울산과학대학 2000 연구논문집 Vol.27 No.1

본 연구는 자체 제작한 전체 패드가 부착된 드로잉 금형을 이용하여 SUS, 연강, AI, 6:4황동 판재를 드로잉 가공하여 생산된 제품의 특성을 자유드로잉 하여 얻은 제품의 특성과 비교 분석하였다. SUS 판재의 경우 제품에 발생하는 현상은 벽 주름, 구변주름, 수직 파단, 드로잉상처, 이어링이 발생하였으며 길이변화는 펀치어깨부분에서 가장 많이 늘어남을 볼 수 있었고 벽 주름 부분에 있어서 접혀진 부분은 상대적으로 적게 늘어남을 볼 수 있었다. 연강 판재는 SUS 판재에서 보여준 현상을 나타내었으나 SUS 판재에 비해 수직 파단은 적게 일어난 반면 이어링이 더 크게 일어났다. AI 판재의 경우 수직 파단은 일어나지 않았으나 플랜지 주름과 밑면터짐이 발생하였다. 6:4황동의 경우는 전체패드의 AI 판재 드로잉에서와 같이 밑면터짐과 플랜지 주름의 발생이 일어났다.

플랜지가 있는 제품에서 부분패드의 영향에 관한 연구

고관영,허주환,문정효,장재석,김동윤,정민섭,김주찬,박기용,이강연,조명우,이권진,조영호,이효걸,김주호,이경희 울산과학대학 2000 연구논문집 Vol.27 No.1

본 논문에서는 기존의 Motion-JPEG 기반 감시시스템에서 낮은 동영상 압축성능 문제를 해결하기 위한 새로운 동영상 압축기법을 제안하였다. 제안된 방법에서는 현재 프레임의 JPEG 데이터 중 변화된 압축 데이터만이 실시간으로 추출하고 저장된다. 제안된 방법에 의해 저장된 데이터는 기존의 JPEG과는 다른 고유의 포맷을 가지기 때문에, 동영상 데이터는 더욱 안전하게 유지될 수 있다. 실험을 통해, 제안된 동영상 압축기법의 압축률이 기존의 Motion-JPEG 기반 감시시스템에 비해 3배정도 높다는 것을 확인할 수 있었다.

L-형 파이프 내 볼밸브 유동에 대한 RANS와 LES 수치해석

배기화(K.H. Bae),허형석(H.S. Heo),강상모(S.M. Kang) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.10

Numerical simulations are performed using RANS and LES on flow through a ball valve for L-shaped pipe. Turbulence models adopted for RANS and LES simulations are k-ε model, Sear Stress Transport(SST) model and LES model. The water with 5000 is exerimentally studied by CFX which is useful simulater in flow. Result of simulations are compared with each other model, that is k-ε, SST and LES, in pressure. There's some diffrence between RANS model and LES. LES model has more thaw pressure result.

Modeling the effects of surfactant, hardness, and natural organic matter on deposition and mobility of silver nanoparticles in saturated porous media

Park, C.M.,Heo, J.,Her, N.,Chu, K.H.,Jang, M.,Yoon, Y. Pergamon Press 2016 Water research Vol.103 No.-

This study aims to provide insights into the mechanisms governing the deposition and retention of silver nanoparticles (AgNPs) in saturated porous media. Column experiments were conducted with quartz sand under saturated conditions to investigate the deposition kinetics of AgNPs, their mobility at different groundwater hardnesses (10-400 mg/L as CaCO<SUB>3</SUB>), and humic acid (HA, 0-50 mg/L as dissolved organic carbon [DOC]). An anionic surfactant, sodium dodecyl sulfate (SDS), was used as a dispersing agent to prepare a SDS-AgNPs suspension. The deposition kinetics of AgNPs were highly sensitive to the surfactant concentration, ionic strength, and cation type in solution. The breakthrough curves (BTCs) of SDS-AgNPs suggested that the transport and retention were influenced by groundwater hardness and HA. At low water hardness and high HA, high mobility of SDS-AgNPs was observed in saturated conditions. However, the retention of SDS-AgNPs increased substantially in very hard water with a low concentration of HA, because of a decreased primary energy barrier and the straining effect during the course of transport experiments. A modified clean-bed filtration theory and a two-site kinetic attachment model showed good fits with the BTCs of SDS-AgNPs. The fitted model parameters (k<SUB>att</SUB> and k<SUB>str</SUB>) could be used successfully to describe that the retention behaviors were dominated by electrostatic and electrosteric repulsion, based on extended Derjaguin-Landau-Vaerwey-Overbeek calculations.

Effect of preparation conditions on the indium species in fully indium exchanged zeolite LTA

Nsanzimana, J.M.V.,Kim, C.W.,Heo, N.H.,Seff, K. Elsevier 2016 Microporous and mesoporous materials Vol.225 No.-

<P>Three fully indium-exchanged zeolite A (LTA) crystals, In-A, were prepared by the reaction of fully dehydrated TI-A with indium metal at 623, 673, and 723 K. Three additional crystals were prepared as above and then hydrated, washed with water, and redehydrated (post-treatment). All six structures were determined crystallographically with synchrotron X-radiation and refined in the space group Pm (3) over barm. Monatomic In+ ions predominate in all crystals: ca. 63-83 atomic % of the In atoms present are monatomic In+ at 6- and 8-ring positions. Tetrahedral In-5(7+) clusters are always found in the sodalite cavities, occupying from 9% to 82% of them. Before post-treatment, only In+, In-5(7+), and In3+ were found, and the In+ population was greatest after the 673 K reaction. The In-5(7+) population decreases monotonically with increasing reaction temperature due to its disproportionation to In+ and In3+. Between 673 K and 723 K, In+ begins to disproportionate also, to In3+ and In-0. Post-treatment continues the extent of these disproportionations to In3+ and In-0. Some of the In-0 atoms produced bridge between remaining In+ ions to form In-3(2+) and In-7(5+). The remainder have moved to the surface of the zeolite crystal. (C) 2016 Elsevier Inc. All rights reserved.</P>

Conformation-specific ultraviolet spectroscopy of benzo-18-crown-6 complexes with a potassium cation

Choi, C.M.,Baek, J.Y.,Park, K.S.,Heo, J.,Kim, N.J. North Holland ; Elsevier Science Ltd 2014 Chemical physics letters Vol.593 No.-

We investigate conformation-specific UV spectra of benzo-18-crown-6 complexes with a potassium cation using a UV-UV hole burning (HB) technique developed for ions in a quadrupole ion trap. Three different UV-UV HB spectra are obtained: two spectra represent the electronic spectra of conformers, K-a and K-b, respectively, and the third exhibits the transitions of a vibrationally 'hot' K-b conformer. These demonstrate that the UV-UV HB technique, of which the applicability was first tested only for ions of a single isomer, can be used to differentiate vibronic peaks of ions existing as two or more different conformers including their vibrationally 'hot' species.