Smooth backfitting in generalized additive models

Yu, K.,Park, B.U.,Mammen, E. IMS INSTITUTE OF MATHEMATICAL STATISTICS 2008 The Annals of statistics Vol.36 No.1

Efficient planning of NPC cluster movement in computer game environment

Springer Science + Business Media 2015 CLUSTER COMPUTING Vol.18 No.1

Relationship between the tertiary structures of mastoparan B and its analogs and their lytic activities studied by NMR spectroscopy

Yu, K.,Kang, S.,Park, N.,Shin, J.,Kim, Yangmee 부산대학교 유전공학연구소 2000 분자생물학 연구보 Vol.16 No.-

Mastoparan B (MP-B), an antimicrobial cationic tetradecapeptide amide isolated from the venom of the hornet Vespa basalis, is an amphiphilic x-helical peptide. MP-B possesses a mariety of biological activities, such as mast cells degradation histamine release, erythrocyte lysis and inhibition of the growth of Gram-positive and Gram-negative bacteria. In order to study the relationship between the structure and the biological activity of MP-B, we used four analogs by replacing amino acids with alanine. Tertiary structures of MP-B and its analogs in 2,2,2-trifluoroethanol (TFE)-containing aqueous solution have been determined by NMR spectroscopy and molecular modeling. The results indicate that [Ala^4]MP-B and [Ala^12]MP-B with higher hydrophobicity adopt a higher content of amphiphilic helical structures, and have better antimicrobial and hemolytic activities than MP-B. However, [Ala^3]MP-B and [Ala^9]MP-B and hydrophobicity have disordered structures. [Ala^3]MP-B and [Ala^9]MP-B have low antimicrobial activity and much less hemolytic activity relative to MP-B. It is likely that tryptophan residue in MP-B and appropriate hydrophobicity of MP-B to induce x-helical structure is essential for the antibacterial and hemolytic activity of MP-B. This study can aid understanding of the structure-activity relationship of MP-B and to design peptides to possess lytic activity.

Comparison of 90‐day case‐fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis

Yu, K‐,H.,Hong, K‐,S.,Lee, B‐,C.,Oh, M‐,S.,Cho, Y‐,J.,Koo, J‐,S.,Park, J‐,M.,Bae, H‐,J.,Han, M‐,K.,Ju, Y‐,S.,Kang, D‐,W.,Appelros, P. Blackwell Publishing Ltd 2011 Acta neurologica Scandinavica Vol.123 No.5

<P>Yu K‐H, Hong K‐S, Lee B‐C, Oh M‐S, Cho Y‐J, Koo J‐S, Park J‐M, Bae H‐J, Han M‐K, Ju Y‐S, Kang D‐W, Appelros P, Norrving B, Terent A. Comparison of 90‐day case‐fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis. 
Acta Neurol Scand: 2011: 123: 325–331. 
© 2010 John Wiley & Sons A/S.</P><P><B>Background – </B> It has not been clarified whether the disparity in ischemic stroke outcome between populations is caused by ethnic and geographic differences or by variations in case mix. Propensity score matching (PSM) analysis can overcome some analytical problems but is rarely used in stroke outcome research. This study was to compare the ischemic stroke case‐fatality between two PSM cohorts of Sweden and Korea.</P><P><B>Methods – </B> Prognostic variables related to baseline characteristics and stroke care were included in our PSM model. Then, we selected 7675 Swedish and 1220 Korean patients with ischemic stroke from each stroke registers and performed one‐to‐one matching based on propensity scores of each patient.</P><P><B>Results – </B> After PSM, all measured variables were well balanced in 1163 matched subjects, and the 90‐day case‐fatality was identical 6.2% (HR 0.997, 95%CI 0.905–1.099) in Sweden and Korea.</P><P><B>Conclusions – </B> No difference is found in the 90‐day case‐fatality in propensity score‐matched Swedish and Korean patients with ischemic stroke.</P>

Solution structure of a cathelicidin-derived antimicrobial peptide, CRAMP as determined by NMR spectroscopy

Yu, K.,Park, K.,Kang, S.-W.,Shin, S.Y.,Hahm, K.-S.,Kim, Y. 부산대학교 유전공학연구소 2002 분자생물학 연구보 Vol.18 No.-

CRAMP was identified from a cDNA clone derived from mouse femoral marrow cells as a member of cathelicidin-derived antimicrobial peptides. This peptide shows potent antimicrobial activity against gram-positive and gram-negative bacteria but no hemolytic activity against human erythrocytes. CRAMP was known to cause rapid permeabilization of the inner membrane of Escherichia coli. In this study, the structure of CRAMP adopts a mainly x-helical conformation in TFE/H_2O solution, DPC micelles, SDS micelles and liposomes, whereas it has a random structure in aqueous solution. The tertiary structure of CRAMP in TFE/H_2O (1:1, v/v), as determined by NMR spectroscopy, consists of two amphipathic α-helices from Leu^4 to Lys^10 and from Gly^16 to Leu^33. These two helices are connected by a flexible region from Gly^11 to Gly^16. Previous analysis of series of fragments composed of various portion of CRAMP revealed that an 18-residue fragment with the sequence from Gly^16 to Leu^33 was found to retain antibacterial activity. Therefore, the amphipathic x-helical region from Gly^16 to Leu^33 of CRAMP plays important roles in spanning the lipid bilayers as well as its antibiotic activity. Based on this structure, novel antibiotic peptides having strong antibiotic activity, with no hemolytic effect will be developed.

Graphene Veils and Sandwiches

Yuk, Jong Min,Kim, Kwanpyo,Alemá,n, Benjamí,n,Regan, William,Ryu, Ji Hoon,Park, Jungwon,Ercius, Peter,Lee, Hyuck Mo,Alivisatos, A. Paul,Crommie, Michael F.,Lee, Jeong Yong,Zettl, Alex American Chemical Society 2011 NANO LETTERS Vol.11 No.8

<P>We report a new and highly versatile approach to artificial layered materials synthesis which borrows concepts of molecular beam epitaxy, self-assembly, and graphite intercalation compounds. It readily yields stacks of graphene (or other two-dimensional sheets) separated by virtually any kind of “guest” species. The new material can be “sandwich like”, for which the guest species are relatively closely spaced and form a near-continuous inner layer of the sandwich, or “veil like”, where the guest species are widely separated, with each guest individually draped within a close-fitting, protective yet atomically thin graphene net or veil. The veils and sandwiches can be intermixed and used as a two-dimensional platform to control the movements and chemical interactions of guest species.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2011/nalefd.2011.11.issue-8/nl201647p/production/images/medium/nl-2011-01647p_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl201647p'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl201647p'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl201647p'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl201647p'>ACS Electronic Supporting Info</A></P>

Antibacterial Effect of Eucalyptus Oil, Tea Tree Oil, Grapefruit Seed Extract, Potassium Sorbate, and Lactic Acid for the development of Feminine Cleansers

Yuk, Young Sam The Institute of Internet 2021 International Journal of Internet, Broadcasting an Vol.13 No.2

Purpose: It has been reported that the diversity and abundance of microbes in the vagina decrease due to the use of antimicrobial agents, and the high recurrence rate of female vaginitis due to this suggests that a new treatment is needed. Methods: In the experiment, we detected that 10% potassium sorbate solution, 1% eucalyptus oil solution, 1% tea tree oil solution, 400 µL/10 mL grapefruit seed extract solution, 100% lactic acid, 10% acetic acid solution, and 10% lactic acid solution were prepared and used. After adjusting the pH to 4, 5, and 6 with lactic acid and acetic acid in the mixed culture medium, each bacterium was inoculated into the medium and incubated for 72 h at 35℃. Incubate and 0 h each. 24 h. 48 h. The number of bacteria was measured after 72 h. Results: In the mixed culture test between lactic acid bacteria and pathogenic microorganisms, lactic acid bacteria showed good results at pH 5-5.5. Potassium sorbate, which has varying antibacterial activity based on the pH, killed pathogenic bacteria and allowed lactic acid bacteria to survive at pH 5.5. Conclusion: The formulation ratio obtained through this study could be used for the development of a feminine cleanser that can be used as a substitute for antibacterial agents. Further, the findings of this study may be able to solve the problem of antimicrobial resistance in the future.

Syntactic Properties of Be-to-V Constructions

Yuk, Jun-Cheol 신영어영문학회 2019 신영어영문학 Vol.72 No.-

Knowledge of a language involves understanding grammatical properties such as word order and the syntactic system of that language and being able to apply these in practice. In this respect, English sentences have similar patterns, but their structures and syntactic properties can differ. For this reason, this paper analyzes the syntactic relation between a nominal infinitive and an adjectival infinitive in similar Be-to-V constructions, based on traditional school grammar. It is then suggested that existing adjectival infinitive use from Be-to-V constructions should be revised and considered as one grammatical unit of a modal idiom <Be+to>, as in ‘used to,’ ‘have to,’ ‘ought to,’ and ‘had better.’ The paper finally attempts to demonstrate that this alternative to the two different Be-to-V constructions provides a persuasive explanation for their identical superficial structure, and can help middle and high school students to understand more clearly the different grammatical properties and meanings of the superficially identical Be-to-V constructions.

과학기술위성 1호 원자외선 분광기 FIMS의 배플 설계

Yuk, I.S.,Seon, K.I.,Ryu, K.S.,Jin, H.,Park, J.H,Nam, U.W.,Lee, D.H.,Oh, S.H.,Rhee, J.G.,Han, W.Y.,Min, K.W.,Edelstein, Jerry,Korpela, Eric 한국천문학회 2003 天文學論叢 Vol.18 No.1

FIMS (Far-ultraviolet IMaging Spectrograph) is the main payload of STSAT-1 satellite which was successfully launched on September 27, 2003. The optical system of FIMS consists of two sets of parabolic cylinder mirror, slit, ellipsoidal reflection grating, and baffle system. We designed two types of baffle system for the FIMS: FOV baffle and order baffle. FOV baffle in the mirror house controls the field of view, and the order baffle in the vacuum box blocks the rays reflected rays by different orders.

External reinforcement of hydrocarbon membranes by a three-dimensional interlocking interface for mechanically durable polymer electrolyte membrane fuel cells

Yuk, Seongmin,Yuk, Jinok,Kim, Tae-Ho,Hong, Young Taik,Lee, Dong-Hyun,Hyun, Jonghyun,Choi, Sungyu,Doo, Gisu,Lee, Dong Wook,Kim, Hee-Tak Elsevier 2019 Journal of Power Sources Vol.415 No.-

<P><B>Abstract</B></P> <P>Although, the use of hydrocarbon membranes is one of the ways to reduce the cost of polymer electrolyte membrane fuel cells, it cannot be practically adopted due to its low mechanical durability under a dynamic wet/dry operation. Here, we present an externally-reinforced hydrocarbon membrane achieved by a three dimensional interlocking interfacial layer which forms a strong interfacial bonding between the hydrocarbon membrane and the catalyst layers. Although a conventional hydrocarbon membrane is easily delaminated from gas diffusion electrodes, the use of the three dimensional interlocking interfacial layer, prepared with a polystyrene nanoparticle template method, enhances the interfacial adhesion by 207 times. The hydrocarbon membrane, tightly connected to the gas diffusion electrodes by the three dimensional interlocking interfacial layers, has a humidity cycling durability that is 1.9 times higher in the membrane electrode assembly level by restricting the dimensional change of the membrane. Furthermore, due to the proton conducting property of the three dimensional interlocking interfacial layer, the external reinforcement does not cause any power performance losses.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An externally-reinforced hydrocarbon (HC) membrane is demonstrated. </LI> <LI> 3D interlocking interface tightly binds the HC membrane and gas diffusion electrode. </LI> <LI> The mechanical stability of the HC membrane is improved by 3D interlocking interface. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>