• 한국연초학회지
• /
• 제14권1호
• /
• pp.24-32
• /
• 1992

The present study was conducted to compare the relative efficiency of two different haploid breeding methods in tobacco varietal development. A single F t hybrid plant from cross of two flue-cured cultivars of Nicotiana tabacum L., Bright Yellow4(BY4) and NC 95, was used to develop the 30 dihaploid lines by anther culture(F1-ADH) and maternally-derived doubled haploid utilizing Nicotiana africana(F1-MDH), respectively. As compared with mid-parent, ADH lines showed increasing in number of leaves, delaying in days to flower and narrowing in leaf width. However, no significant differences in the other characters investigated were recognized. MDH lines also showed narrow leaf width, while no significant differences in the other characters were observed. The variations of the characters investigated were generally greater in ADH than MDH lines. MDH lines had higher plant height and shorter days to flower than ADH lines, while other characters did not show remarkable differences. The degree of heritability for each of the characters observed between ADH and MDH was almost the same. The characters showing high heritability value were plant height, leaf number, days to flower, and yield, while those showing relatively low value were leaf length, leaf width, and total alkaloid content. Predicted gains from selection for increased yield were calculated for both populations(F1-ADH, F1-MDH) and correlated responses associated with selection for yield were estimated. Plant height, leaf width, days to flower, percent reducing sugar and disease resistance would be expected to improve with selection for yield much faster in the MDH population than in the ADH.

• Asian-Australasian Journal of Animal Sciences
• /
• 제16권9호
• /
• pp.1242-1246
• /
• 2003

Data pertained to 335 crossbred cows comprising of 1/2 Friesian (F) + 1/2 Hariana (H), 1/2 F + 1/4 Jersey (J) + 1/4 H, 1/2 F + 1/4 Brown Swiss (BS) + 1/4 H, 1/2 F + 1/4 Red Dane (R) + 1/4 H, FR (I) and FRH (I) genetic groups extending over a period of 21 years (1970-1990) maintained at Animal Farm of CCS HAU, Hisar. The averages for first lactation milk yield was $2,486.24{\pm}80.26kg$ and peak yield of first three lactation were $11.35{\pm}0.72kg$, $13.97{\pm}0.60kg$ and $16.02{\pm}0.42kg$, respectively. The lifetime milk production was observed as $11,305.16{\pm}1,004.52kg$ in crossbred cattle. The average first lactation fat yield was observed as $102.06{\pm}0.01kg$ and peak fat yield of first three lactation were $0.458{\pm}0.01$, $0.490{\pm}0.01$ and $0.500{\pm}0.02kg$, respectively. The lifetime fat production was estimated as $502.31{\pm}45.90kg$. LTMP and LTFP had reasonably good additive genetic variance which could be exploited either through mass selection/combined with family or pedigree selection. FLMY, peak yields and LTMP had significant positive phenotypic correlation with FLFY and LTFP and the correlation at the genetic level were also higher and positive for these traits. Finally, peak week milk yield of first lactation (PMY1) was the earliest available trait having desirable and significant correlation at phenotypic and positive at genetic level with FLFY, PFY1 and PFY2, PFY3 and LTFP and selection for this trait will help in early evaluation of sires and dams and will increase genetic advancement per unit of time.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권5호
• /
• pp.1303-1315
• /
• 2012

In the draft of the IEEE 802.11s standard, a tree topology is established by the proactive tree-building mode of the Hybrid Wireless Mesh Protocol (HWMP). It is used for cases in which the root station (e.g., gateway) is an end point of the majority of the data connections. In the tree topology, the root or central stations (e.g., parent stations) are connected to the other stations (e.g., leaves) that are one level lower than the central station. Such mesh stations are likely to suffer heavily from contention in bottleneck links when the network has a high traffic load. Moreover, the dependence of the network on such stations is a point of vulnerability. A failure of the central station (e.g., a crash or simply going into sleep mode to save energy) can cripple the whole network in the tree topology. This causes performance degradation for end-to-end transmissions. In a connected mesh topology where the stations having two or more radio links between them are connected in such a way that if a failure subsists in any of the links, the other link could provide the redundancy to the network. We propose a scheme to utilize this characteristic by organizing the network into concentric tiers around the root mesh station. The tier structure facilitates path recovery and congestion control. The resulting mode is referred to as Tier-based Proactive Path Selection Mode (TPPSM). The performance of TPPSM is compared with the proactive tree mode of HWMP. Simulation results show that TPPSM has better performance.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.420-422
• /
• 2004

The non-ideal characteristics of wireless communication are found in sensor network. And sensor network must also address new raised issues. The efficient ad-hoc routing algorithm is considered the nice solution for new raised sensor network problems. To design this efficient ad-hoc routing algorithm, we study and evaluate new components in routing algorithm. Namely, new components are Link estimator, Neighbor table and Parent selection. We have tested this related experiment using the TIP-30C. TIP-30C is sensor network node that is designed by KETI(Korea Electronic Technology Institute).

• International Journal of Industrial Entomology and Biomaterials
• /
• 제25권2호
• /
• pp.147-151
• /
• 2012

Fifteen races resulted from silkworm breeding program at Sericulture Research Department (SRD) were used for hybridization. Fourteen hybrids were obtained and coded as; Giza C, D, R, S, T, U, A, V, W, P, H, L and Qanater 1, 2. The traits of cocoon weight, cocoon shell weight, pupal weight, cocoon shell ratio, silk productivity, fifth instar duration, total larval duration, number of cocoon per liter and pupation ratio were evaluated. Data were analyzed by using three formulae of heterosis over better, mid and check parent values. Hybrids of Giza V, C, N, Qanater 1 and 2 are promising and could be used in commercial cocoon production. Generally, there are some new hybrids can be exploited in commercial scale. Also, the local races can be evolved using the hybridization, inbreeding and selection program.

• 한국미생물·생명공학회지
• /
• 제17권2호
• /
• pp.131-135
• /
• 1989

Effects of the inoculum size of testing organism and pH of the plate and the concentration of agar were investigated for the selection of high kasugamycin producing mutants of Streptomyces kasugaensis ATCC 15114. For the detection of high kasugamycin-producing mutants, both concentrations of agar and test organism were optimized at the concentrations of 2% and 0.35 (A$_{550}$), respectively. The pH 7 was optimum for both growing the testing organism, Pseudomonas fluorescens IFO 12180, and for obtaining more promising mutant strains of S. kasugaensis. Under these conditions, mutants had been isolated which, tested later in liquid cultures, gave higher kasugamycin yields than that of the parent strain.

• 미생물학회지
• /
• 제17권3호
• /
• pp.152-159
• /
• 1979

Using Micromonospora strain, gentamicin was produced by fermentation. The increase in gentamicin productivity was studied by strain improvement and systematic optimization of fermentation process variables. The productivity of parent strain of M.purpurea (ATCC15835) was improved by selection of superior mutant after U.V. irradiation and induction of genetamicin resistance. Potato starch and soy bean meal were the best carbon and nitrogen sources for gentamicin fermentation, respectively. The optimum stimulating concentration of Co ion for gentamicin production was 0.006g $CoCl_2$ per liter of broth. Oxygen ws found to be an important factor for gentamicin yield. The optimum pH for the cell growth and gentamicin production were 7.2 and 6.8 respectively. By controlling the pH, oxygen, and other conditions found in this study at the optimal conditions for cell growth and gentamicin production, the total productivity of gentamicin was increased significantly.

• 지역사회간호학회지
• /
• 제18권1호
• /
• pp.136-145
• /
• 2007

Purpose: This study was attempted to illuminate danger signals through an extensive analysis of factors influencing adolescents' illicit drug use. On this basis, it built predictive factors of adolescents' illicit drug use. Method: A questionnaire was distributed to 1,238 subjects living in Seoul, and of them 1,082 answers were analyzed using the SAS 8.2 program. Also logistic regression analysis was conducted based on the stepwise selection method for constructing the predictive factors. Results: The findings of this study are as follows. Individual-related factors were psycho-somatic symptoms, self-esteem, fortune delinquent experience, and sexual-violence delinquent experience. Home-related factors were insincerity, threatening and the assessment of the parent (rearer)-adolescent communication type. Society-related factors were affection of friends and friends' attitude toward delinquency. Conclusion: These findings of this study suggest that a broad intervention program should be provided to nurture wholesome youth culture related to illicit drug use. It is also recommended that a variety of individual, home and society-related programs should be developed for drug users.

• ETRI Journal
• /
• 제28권6호
• /
• pp.709-720
• /
• 2006

In this paper, we suggest a simple and efficient multiple-forwarder-based file distribution method which can work with a tree-based application layer multicast. Existing multiple-forwarder approaches require high control overhead. The proposed method exploits the assumption that receivers join a session at different times. In tree-based application layer multicast, a set of data packets is delivered from its parent after a receiver has joined but before the next receiver joins without overlapping that of other receivers. The proposed method selects forwarders from among the preceding receivers and the forwarder forwards data packets from the non-overlapping data packet set. Three variations of forwarder selection algorithms are proposed. The impact of the proposed algorithms is evaluated using numerical analysis. A performance evaluation using PlanetLab, a global area overlay testbed, shows that the proposed method enhances throughput while maintaining the data packet duplication ratio and control overhead significantly lower than the existing method, Bullet.

• 대한가정학회지
• /
• 제49권4호
• /
• pp.51-65
• /
• 2011

In order to find out better policy strategies for public nanny service, this study tried to find out the characteristics and the major problems of this service based on 24 in-depth interviews and 7 focus group interviews with nannies, beneficiaries, managers, and public agents. Research findings showed that public nanny service was effectively filling the gap between nursery care services and parent's care services(especially who are both working). Also, this service provided tailored support to parents who have urgent or unexpected problems which prohibit them from properly caring their children. Especially this service effectively worked for temporary needs of caring young children. This study proposes these two strategies as follows: First, the beneficiary selection criteria should be updated. Second, the level and types of available time should be raised to fit the diverse needs of parents.