• Korean Journal of Plant Resources
• /
• v.9 no.3
• /
• pp.243-248
• /
• 1996

The yield and quality of black medick seeds(Medicago lupulina L.) produced from different fertilization and flowering position was investigated was investigated to develop the technology of seed vigor maintenance. Number of flowers and seeds, 100 seeds weight, yellow seed percentage, and large seed percentage were higher in seeds produced from stems than in those from branches. Increase of nitrogen resulted in a higher rate of yellow and large seeds as well as 160 seeds weight. Germination rate was the highest (56.9%) in the yellow seeds harvested from stems which were grown with a treatment of lower level of nitrogen and higher level of phosphorus. Malformed seedlings were frequently observed among the seedlings grown from seeds which were produced only with phosphorus.

• Journal of Korean Society of Forest Science
• /
• v.83 no.3
• /
• pp.372-379
• /
• 1994

Timber harvesting impacts on soil microbial populations and respiration rates were examined in naturally regenerating trembling aspen(Populus tremuloides Michx.) stands on two contrasting soils, an Omega loamy sand (sandy mixed, frigid Typic Udipsamment) and an Ontonagon clay loam (very fine, mixed Glossic Eutroboralf). Five timber harvesting disturbances were simulated during winter of 1990 and spring of 1991, including commercial whole-tree harvesting(CWH), winter logging trail+CWH, logging slash removal+CWH(LSR), forest floor removal+LSR(FFR), and spring compaction+FFR. Regardless of soil types, total soil respiration rates of each stand decreased slightly or remained the same after harvesting while microbial population increased progressively during the first two years following harvesting. Microbial populations increased more rapidly and constantly at the sandy site than at the clayey site, which may indicate that the soil physical and chemical conditions changed more drastically for microbial activity following timber harvesting at the sandy site than at the clayey site. However, two kinds of treatment applications-three levels of organic matter removal and two levels of compaction-did not result in significant differences in microbial population or total soil respiration rate at each site during the first two post-harvest years. Total soil respiration of the aspen stands, sum of root respiration and microbial respiration, was a poor index for the microbial activity in this study because aspen kept an active root system for the successive root-sprouts even after harvesting, which resulted in a large portion of root respiration in total respiration.

• Polymer(Korea)
• /
• v.28 no.2
• /
• pp.143-148
• /
• 2004

${\alpha}$,$\omega$-Hydrogen polyorganosiloxane(HPMDMS) prepolymer was prepared from equilibrium polymerization ofoctamethylcyclotetrasiloxane, 1,3,5-trimethylcyclotrisiloxane, 1,3,5,7-tetravinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane, and 1,1,3,3-tetramethyl disiloxane as an end-blocker in the presence of tetramethylammonium siloxanolate as a catalyst. Polyorganosiloxane modified with dimethylacrylamide(APMDMS) was prepared by hydrosilylation of HPMDMS with dimethylacrylamide in the presence of Pt catalyst, and followed by coordination of metal oxide (APMDMS-MO), such as NiO and FeO, to the amide moieties of the resulting polymer. The chemical structures of HPMDMS and APMDMS were confirmed by FT-IR and $^1$H-NMR analysis. Liquid silicone rubber containing metal oxide composite (LSRMO) was prepared by compounding APMDMS-MO, ${\alpha}$,$\omega$-vinylpolydimethylsiloxane, and a catalyst in a high speed dissolver. The thermal conductivity of LSRMO composite was determined to be 0.29 W/mK, and the volume resistivity exhibited a lower value than that of LSR composite. The mechanical and thermal properties of LSRMO and LSR composite were measured by UTM and TGA.

• Parasites, Hosts and Diseases
• /
• v.49 no.4
• /
• pp.381-384
• /
• 2011

The first human case with trichinellosis was reported in 1964 in Tibet, China. However, up to the present, the etiological agent of trichinellosis has been unclear. The aim of this study was to identify a Tibet Trichinella isolate at a species level by PCR-based methods. Multiplex PCR revealed amplicon of the expected size (173 bp) for Trichinella spiralis in assays containing larval DNA from Tibet Trichinella isolate from a naturally infected pig. The Tibet Trichinella isolate was also identified by PCR amplification of the 5S ribosomal DNA intergenic spacer region (5S ISR) and mitochondrial largesubunit ribosomal RNA (mt-lsrDNA) gene sequences. The results showed that 2 DNA fragments (749 bp and 445 bp) of the Tibet Trichinella isolate were identical to that of the reference isolates of T. spiralis. The Tibet Trichinella isolate might be classifiable to T. spiralis. This is the first report on T. spiralis in southwestern China.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11b
• /
• pp.1595-1598
• /
• 2002

네트워크 장애로 인한 인터넷 서비스 품질의 저하는 사용자와 서비스 제공자에게 여러 가지 형태로 손실을 가져오므로 망의 우회경로 설정 및 복구방안은 중요한 요소가 되고 있다. 망 복구에 있어서 중요한 과제는 작업 경로(working path)에 대한 복구 경로(restoration path)를 설정하는 것이다. 장애가 발생하더라도 서비스의 중단이 없도록 하기 위해서는 복구 경로를 설정할 때 작업 경로의 대역을 보장할 수 있는 복구 경로를 실정해야 한다. 이를 위해 MPLS망에서는 명시적 Routing기법에 기반을 둔 Constraint-based routing이 제안되었고 또한 망의 경로 복구를 위해 정적 및 동적설정기법이 제안되고 있다. 본 논문에서 제안된 방식은 확장된 OSPF 프로토콜의 TE-LSAs를 이용하여 또 다른 virtual 망을 구성하고 기본경로 중간의 TE-LSR을 새로운 PIL로 설정하여 빠른 대체 LSP를 설정 및 복구하는 기법을 성능 비교를 통해 망 자원의 효율적 사용을 보고자 한다.

• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.115-118
• /
• 2015

We made phase-referencing Very Long Baseline Interferometry (VLBI) observations of Galactic 22 GHz $H_2O$ maser sources with VLBI Exploration of Radio Astrometry (VERA). We measured the parallax distances of G48.61+0.02, G48.99-0.30, G49.19-0.34, ON1, IRAS 20056+3350, IRAS 20143+3634, ON2N, and IRAS 20126+4104, which are located near the tangent point and the Solar circle. The angular velocity of the Galactic rotation at the LSR (i.e. the ratio of the Galactic constants) is derived using the measured parallax distances and proper motions of these sources. The derived value of ${\Omega}_0=28.8{\pm}1.7km\;s^{-1}kpc^{-1}$ is consistent with recent values obtained using VLBI astrometry but 10% larger than the International Astronomical Union (IAU) recommended value of $25.9km\;s^{-1}kpc^{-1}=(220km\;s^{-1})$ / (8.5 kpc).

• The KIPS Transactions:PartC
• /
• v.9C no.1
• /
• pp.45-54
• /
• 2002

MPLS(Multiprotocol Label Switching) is regarded as a core technology for migrating to the next generation Internet. In this paper, we propose an dynamic flow admission control supporting DiffServ(Differentiated Services) to provide QoS in MPLS networks. Our proposed model dynamically adjusts the amount of admissible traffic based on transmittable capacity over one outgoing port. It then transmits the Packets while avoiding congested area resulting traffic loss. Ingress LSRs find out the congested area by collecting network state information at QoS state update for QoS routing table. Our Proposed model manages the resource efficiently by protecting the waste of resources that is a critical Problem of DiffServ and makes much more flows enter the network to be served.

• Journal of KIISE:Information Networking
• /
• v.33 no.6
• /
• pp.461-472
• /
• 2006

In this paper, we propose a novel on-demand multicasting algorithm, 'Durable Distance Vector Multicasting(DDVM),' for Mobile Ad hoc Network(MANET). DDVM has a more efficient routing-control complexity than Link State Routing(LSR) and with the smaller complexity, DDVM provides a high delivery ratio for MANET with high mobility by adapting to dynamic topological changes. This is achieved by adding 'combined path durability' statistic into the routing-control information of Distance Vector Routing(DVR). The routing-path duration statistic is computed in a fully distributed manlier at each node in the network based on only local information from neighbour nodes. We show by simulation studies the effectiveness of DDVM compared with On-demand Multicast Routing Protocol(ODMRP).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.4
• /
• pp.1859-1864
• /
• 2014

Liquid silicone rubber(LSR) has been applied to various products such as electronic devices owing to its excellent thermal and chemical resistance. Hyperelastic materials, however, have properties distinguished from general metal materials. Hyperelastic materials show elastic behaviors in the range of large deformation in which load has the nonlinear relation with deformation. In addition, they have characteristics of nonlinearity, incompressibility, in large scale. On account of such characteristics, there are many difficulties in design and production using these materials. In this study, the load-deformation relation obtained from tension and compression tests was applied to finite element analysis in order to design waterproof connectors for automobiles. Furthermore, the effectiveness of the finite element analysis was confirmed by comparing the results of analysis with those of performance tests.

• Journal of The Korean Astronomical Society
• /
• v.47 no.6
• /
• pp.319-325
• /
• 2014

We map two molecular clouds located in the exact anticenter region emitting in the (J = 1-0) transition of $^{12}CO$ and $^{13}CO$ using the 3-mm SIS mixer receiver on the 14-m radio telescope at Taeduk Radio Astronomy Observatory. The target clouds with anomalous velocities of $V_{LSR}{\sim}-20km\;s^{-1}$ are distinguished from other clouds in this direction. In addition, they are located in the interarm region between the Orion Arm and the Perseus Arm. Sizes of the clouds are estimated to be about 8.6 and 10.8 pc, respectively. The total mass is estimated to be about $4{\times}10^3$ $M_{\odot}$ using CO luminosity of the clouds. Several cores are detected, but no sign of star formation is found according to the IRAS point sources. Their larger linewidths, anomalous velocities, and their location at the interarm region make these clouds more distinguished, though their physical properties are similar to the dark clouds in the solar neighborhood in terms of mass and size.