• Title/Summary/Keyword: $Z_2$

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A Study on the Implementation of Multi-touch model using a Haptic Device in Virtual Reality (가상현실에서 Haptic 디바이스를 활용한 멀티터치 모델 구현에 관한 연구)

  • Kang, Im-Chul;Kim, Beom-Seok;Hur, Gi-Taek;Ko, Young-Hyuk
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.4
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    • pp.83-90
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    • 2010
  • In this paper, we use VR technologies including touch processing technologies and haptic devices to offer touch of fish objects to users. The Omni, a kind of haptic device and made by Sensable Inc., is used to implement multi touch model in VR space. In addition, Matlab/Simulink and proSENSE Virtual Touch Toolbox of Handshake Inc., are used as programing tools. Functions needed to describe the movement of x, y, and z axis respectively are applied to delineate the natural movement of fish objects modeled with 3D. Such movements offer realistic physical interactions to two users controlling multi point respectively. In experiment, to perceive the appearance of 3D object by touch and to feel the respiration by touch are well conducted. We also verify that it is possible to develop games or contents through multi participation in VR Space by using multi point.

Geographic Variation in Survival Rate and Height Growth of Pinus densiflora S. et Z. in Korea

  • Kim, In-Sik;Ryu, Keun-Ok;Song, Jeong-Ho;Kim, Tae-Su
    • Journal of Korean Society of Forest Science
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    • v.94 no.2 s.159
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    • pp.73-81
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    • 2005
  • This study was conducted to examine the geographic variation among provenances of Pinus densiflora in survival rate and height growth at four test plantations (Jungsun, Chungju, Naju, and Jeju). The plantations were parts of the eleven provenance trials of Pinus densiflora established by Korea Forest Research Institute in 1996. The survival rate and height growth were significantly different among test plantations at $p{\leq}0.01$. Latitude and longitude of test plantation were negatively correlated with survival rate and height growth. On the other hand, annual mean temperature, mean temperature (Nov.~Feb.), extremely low temperature (Dec.~Feb.), and annual mean growing days of test plantation were positively correlated with these two. The relationships between growth variables and geographic variables were analysed with canonical correlation analysis. A considerable amount of variation in survival rate and height growth was explained by latitude, annual mean growing days, extremely low temperature (Dec.~Feb.) and extremely high temperature (Nov.~Feb.) of provenances. It is estimated that up to 47.1% and 67.4% of the genetic variability in survival rate and height growth was attributable to the environmental variability of the provenances, respectively. The response surface curve of survival rate and height growth was plotted against latitude and longitude to examine growth performance of provenances for each test site. Generally, the local provenances showed better survival rate and height growth.

Comparison of shear bond strength of orthodontic brackets using various zirconia primers

  • Lee, Ji-Yeon;Kim, Jin-Seok;Hwang, Chung-Ju
    • The korean journal of orthodontics
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    • v.45 no.4
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    • pp.164-170
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    • 2015
  • Objective: The aim of this study was to compare the shear bond strength (SBS) of orthodontic brackets bonded to zirconia surfaces using three different zirconia primers and one silane primer, and subjected to thermocycling. Methods: We designed 10 experimental groups following the surface treatment and thermocycling. The surface was treated with one of the following method: no-primer (NP), Porcelain Conditioner (PC), Z-PRIME Plus (ZP), Monobond Plus (MP) and Zirconia Liner Premium (ZL) (n=20). Then each group was subdivided to non-thermocycled and thermocycled groups (NPT, PC, ZPT, MPT, ZLT) (n=10). Orthodontic brackets were bonded to the specimens using $Transbond^{TM}$ XT Paste and light cured for 15 s at $1,100mW/cm^2$. The SBS was measured at a 1 mm/min crosshead speed. The failure mode was assessed by examination with a stereomicroscope and the amount of bonding resin remaining on the zirconia surface was scored using the modified adhesive remnant index (ARI). Results: The SBS of all experimental groups decreased after thermocycling. Before thermocycling, the SBS was ZL, $ZP{\geq}MP{\geq}PC>NP$ but after thermocycling, the SBS was $ZLT{\geq}MPT{\geq}ZPT>PCT=NPT$ (p > 0.05). For the ARI score, both of the groups lacking primer (NP and NPT) displayed adhesive failure modes, but the groups with zirconia primers (ZP, ZPT, MP, MPT, ZL, and ZLT) were associated with mixed failure modes. Conclusions: Surface treatment with a zirconia primer increases the SBS relative to no-primer or silane primer application between orthodontic brackets and zirconia prostheses.

A study on the fabrication of Y-branch for optical power distribution and its coupling properties with optical fiber (광분배를 위한 Y-branch 제작과 광파이버와의 결합특성에 관한 연구)

  • 김상덕;박수봉;윤중현;이재규;김종빈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.12
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    • pp.3277-3285
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    • 1996
  • In this paper, w designed an opical power distribution device for application to an optical switching and an optical subscriber loop. We fabricated PSG thin film by LPCVD. Based on the measured index of fabricted thin film, rib-type waveguide was transformed to two-dimension by the effective index method and we simulated dispersion property to find asingle-mode condition. We found that the optimum design parameters of rib-type waveguide are:cladding layer of 3.mu.m, core layer of 3.mu.m, buffer layer of 10.mu.m, and core width of 4.mu.m. Each side of the guiding region was etched down to 4.mu.m to shape the core. We used these optimum parameters of the rib-type waveguide with branching angle of 0.5.deg. and simulted the Y-branch waveguide by the BPM simulation. Numerical loss in branching area was claculated to be 0.1581dB and equal to the total loss of the Y-branch. The loss of the fabricated Y-branch waveguide on PSG film ws 1.6dB at .lambda.=1.3.mu.m before annealing but was 1.2dB after annealing at 1000.deg. C for 10 minutes. Consequently, the loss of branching area from 3000.mu.m to 6000.mu.m in the z-direction was 0.8dB, and single-mode propagation was confirmed by measuring the near field pattern. For coupling the fabricated Y-branch waveguide with an optical fiber, we fabricated V-groove which was used as the upholder of optical fiber. An etching angle was 54.deg. and the width and depth of guiding groove was 150.mu.m, 70.mu.m, respectively. The optical fiber is inserted onto V-groove. Both the Y-branch and V-groove were connected through the index matching oil. Coupling loss after connecting Y-branch and the optical fiber on V-groove was 0.34dB and that after injecting index mateching oil was 0.14dB.

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Gebrauch und Bedeutung der Personalpronomina der dritten Person im Deutschen (독일어 3인칭 대명사의 사용과 의미)

  • Jin Jeongkun
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.1
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    • pp.189-212
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    • 1999
  • In diesem Aufsatz haben wir uns $zun\"{a}chst\;damit\;besch\"{a}ftigt$, unter welchen Bedingungen die Pronomina der dritten Person korrekt verwendet werden. Doch davor haben wir uns darauf einlassen, wann die Pronomina Restriktionen unterliegen. Die Situationen, in denen die betreffenden Pronomina sowohl grammatisch, als auch kommunikativ korrekt gebraucht werden, sind 1) Prasentation des Referenzobjekts durch den Sprecher, 2) $Auff\"{a}lligkeit$ des Referenzobjekts, 3) Gemeinsame Fokussierung der Kommunikationspartner auf Referenzobjekte, 4) Warten auf das Referenzobjekt und 5) Erinnerung an Referenzobjekte. In diesen Situationen werden verschiedene Faktoren, z.B. die Lage des Referenten im aktuellen Sprechsituation, fur den Pronominagebrauch mitgewirkt. Seit der Antike bilden die Pronomina einen Gegestand der linguistischen Untersuchung. Seitdem werden sie nach unterschiedlichen Aspekten betrachtet und beschrieben. Vor allem wird der Weg der Forschung zu den personalen, aber auch demonstrativen Pronomina durch zwei Begriffe, namlich Deixis und Anaphora, $ma{\ss}geblich$ bestimmt. Im Hinblick darauf haben wir die Frage diskutiert, ob das $Ph\"{a}nomen$ der Anaphora unter dem der Deixis bzw. der Textualdeixis subsumiert werden kann oder nicht. Man kann dafur $pl\"{a}dieren,\;da{\ss}$ Anaphora und Deixis kommunikativ verschiedene Phanomene darstellen $k\"{o}nnte$. Wir neigen allerdings dazu, $da\ss$ es eine semantische $Integrationsm\"{o}glichkeit$ der Anaphora in die(Textual)Deixis gibt. Nach dem Durchmustern verschiedener Verwendungsweisen und theoretischer Positionen haben wir uns mit der Semantik der Pronomina $befa{\ss}t$, die in der Pronominaforschung bisher weitgehend $vernachl\"{a}ssigt$ worde ist. Dabei stellte sich heraus, $da\ss$ die Beeutung des betreffenden Pronomen vor allem durch die Angabe der $Kommunikationssituationsabh\"{a}ngigkeit$ beschrieben werden kann. Damit wurde ein Versuch unternommen, die festgestellten verschiedenen Gebrauchsweisen semantisch zu systematisieren und somit auf eine einheitliche Semantik $zuruckzuf\"{u}hren$.

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Variations in Growth Characteristics and Stress-wave Velocities of Zelkova serrata Trees from Eight Half-sib Families Planted in Three Different Initial Spacings

  • Prasetyo, Agung;Endo, Ryota;Takashima, Yuya;Aiso, Haruna;Hidayati, Fanny;Tanabe, Jun;Ishiguri, Futoshi;Iizuka, Kazuya;Yokota, Shinso
    • Journal of Forest and Environmental Science
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    • v.31 no.3
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    • pp.235-240
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    • 2015
  • Zelkova serrata is an important hardwood species for the timber industry in Japan. Tree breeding programs for this species have mainly focused on growth characteristics such as stem diameter (D), tree height (TH), stem form, and branching. In order to fulfill timber industry needs, wood quality improvement should be included in the tree breeding program of this species. In the present study, growth characteristics, such as D and TH, and the stress-wave velocity (SWV), which is highly correlated with Young's modulus of wood, were measured for 20-year-old Z. serrata from eight half-sib families planted in a progeny test site with three different initial spacings. Significant differences in all the measured characteristics were found among the eight half-sib families. The variance components of the half-sib families for D, TH, and SWV were 27.2%, 47.3%, and 33.5%, respectively. These results indicate that all the measured characteristics of this species could be improved by tree breeding programs. In addition, only low correlation coefficients were obtained between the growth characteristics and SWV, indicating that extensive selection on SWV in tree breeding programs may not always lead to a reduction in yield volume.

A New Record of Asca bicornis Canestrini & Fanzago, 1877 (Acari, Mesostigmata, Ascidae) from Hallasan Mountain in the Republic of Korea (한라산에서 발견된 미기록 응애 Asca bicornis (응애아강, 중기문응애목, 떠돌이응애과)의 보고)

  • Keum, Eunsun;Jung, Chuleui
    • Korean journal of applied entomology
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    • v.57 no.3
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    • pp.191-197
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    • 2018
  • Mites in the family Ascidae are soil dwelling predators of small insects which would have potential to be used as biological control agent. In Korea, 10 genera of 24 species were recorded in the family. During the soil acarine biodiversity study, Asca bicornis Canestrini & Fanzago, 1877 was discovered from moss habitat on Muljangori craer lake 936 m alt in Hallasan mountain in Jeju which was designated as UNESCO Biosphere reserve and World herigate site. We reports this as a new record to Korean Mesostigmata fauna, and provide the morphological description. This species has morphologically characteristic as all dorsal setae nude and needle shaped, lateral caudal projection of Z4 shaped, which are different from the con-general species of A. aphidioides.

A Systematic Review of Bee Venom Acupuncture for Knee Osteoarthritis (무릎 골관절염의 봉독 약침 치료에 대한 체계적 문헌 고찰)

  • Gu, Ji-Hyang;Kim, Eunseok;Park, Yang-Chun;Jung, In Chul;Lee, Eun-Jung
    • Journal of Korean Medicine Rehabilitation
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    • v.27 no.3
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    • pp.47-60
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    • 2017
  • Objectives The aim of this research is to assess the effects of bee venom acupuncture for knee osteoarthritis. Methods For a systematic review, we constructed a key question as the effect of bee venom acupuncture for knee osteoarthritis and selected RCTs and nRCTs. We searched the following 15 databases without a language restriction: Pubmed, EMBASE, Cochrane CENTRAL (CENTRAL), CINAHL, AMED, seven Korean medical databases (KoreaMed, Kmbase, KISS, NDSL, KISTI, Koreantk, OASIS) and three Chinese databases including CNKI, Wanfang and VIP database. Results A total of 300 potentially relevant studies were identified; only 13 studies were selected for systematic review. Almost studies showed that bee venom acupuncture has significant effect on knee osteoarthritis. 5 studies comparing bee venom acupuncture with acupuncture were included in the meta-analysis. The effect size of standardized mean difference (SMD) was analyzed as 'small effect' with 0.47 (95% CI: 0.10~0.83, Z=2.49, p=0.01). Conclusions The research showed that bee venom acupuncture can significantly reduce pain, stiffness and improve the quality of life of patients with knee osteoarthritis. However, most of the studies included in the analysis were evaluated as methodologically high risk of bias. This suggests that there is limitation applying this study. In the future, more Randomized Controlled trial should be actively conducted.

Effect of Reinforcement of Glass fiber on Auto and Heat polymerized denture base resin (유리 섬유의 첨가에 따른 자가중합 및 열중합 의치상용 레진의 강화효과)

  • Yu, Sang-Hui;Kim, Yeoun-Soo;Choi, Un-Jae;Jun, Jong-Nam
    • Journal of Technologic Dentistry
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    • v.31 no.4
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    • pp.37-43
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    • 2009
  • This study evaluated the effect of concentration of glass fiber reinforcement on the flexural properties of auto and heat polymerized denture base resin. The test specimens($64{\times}10{\times}3.3mm$) were made of auto and heat polymerized resin(Vertex, Dentimax, Netherlands). Glass fiber(ER 270FW, Hankuk Fiber Glass, Korea) were used to reinforce the denture base resin. The 2.6%, 5.3% and 7.9% volume pre-impregnated fiber were located at the bottom of specimen. The test specimens(n=7) of each group were stored in distilled water at $37^{\circ}C$ for 50 hours before test. The flexural strength and modulus were measured by an universal testing machine(Z020, Zwick, Germany) at a crosshead speed of 5 mm/min in a three-point bending mode. The data was analyzed by one-way ANOVA and the Duncan's multiple range test(${\alpha}$=0.05). The difference of auto polymerized resin groups and heat polymerized resin groups were statistically analyzed by t-test(${\alpha}$=0.05). Glass fiber showed significant reinforcing effects on auto and heat polymerized resin. For flexural strength and modulus, auto polymerized resin was the highest in 7.9% volume, while heat polymerized resin was the highest in 5.3% volume. In this study, glass fiber at 7.9% volume ratio showed most effective reinforcing effect on auto polymerized resin and glass fiber at 5.3% volume ratio showed most effective reinforcing effect on heat polymerized resin in terms of flexural strength and flexural modulus.

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A redshift survey of the nearby galaxy cluster Abell 2199: comparison of the spatial and kinematic distributions of galaxies and intracluster medium

  • Song, Hyunmi;Hwang, Ho Seong;Park, Changbom;Tamura, Takayuki
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.42.1-42.1
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    • 2017
  • We present the results from an extensive spectroscopic survey of the central region of the nearby galaxy cluster Abell 2199 (A2199) at z=0.03. By combining 775 new redshifts from the MMT/Hectospec observations with the data in the literature, we construct a large sample of 1624 galaxies with measured redshifts at R<30', which redsults in high spectroscopic completeness at $r_{petro,0}$<20.5 (77%). We use these data to study the kinematics and clustering of galaxies, focusing on the comparison with those of the intracluster medium (ICM) from Suzaku X-ray observations. We identify 406 member galaxies of A2199 at R<30' using the caustic technique. The velocity dispersion profile of cluster members appears smoothly connected to the stellar velocity dispersion profile of the cD galaxy. The luminosity function is well fitted with a Schechter function at $M_r$<-15. The radial velocities of cluster galaxies generally agree well with those of the ICM, but there are some regions where the velocity difference between the two is about a few hundred kilometers per second. The cluster galaxies show a hint of global rotation at R<5' with $v_{rot}=300-600kms^{-1}$, but the ICM in the same region does not show such rotation. We apply a friends-of-friends algorithm to the cluster galaxy sample at R<60' and identify 32 group candidates, and examine the spatial correlation between the galaxy groups and X-ray emission. This extensive survey in the central region of A2199 provides an important basis for future studies of interplay among the galaxies, the ICM, and the dark matter in the cluster.

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