• The Plant Pathology Journal
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• v.22 no.3
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• pp.235-238
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• 2006

Chrysanthemum stunt viroid (CSVd) induced systemic symptoms on chrysanthemum. We detected small RNAs of approximately 22 nucleotides with sequence specificity to CSVd in chrysanthemum infected with CSVd: an indication of the presence of RNA silencing. Regardless of symptom differences associated with CSVd, the small RNAs distributed similarly in amount. Small RNAs were detected with partial-length or full-length probes, indicating that they are not restricted to specific viroid regions but likely representing most of the viroid molecule.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.162-172
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• 1997

In this paper, we investigated the performance of a binary feedback switch algorithm for the ABR(Available Bit Rate) service in ATM networks. A binary feedback switch is also called EFCI(Explicit Forward Congestion Indication) switch and can be classificed into input cell processing(IP) scheme according to processing methods for the EFCI bit in data-cell header. We proposed two implementation methods for the binary feedback switch according to EFCI-bit processing schemes, and analyzed the ACR(Allowed Cell Rate) of source and the queue length of switch for each scheme in steady state. In addition, we derived the upper and lower bounds for maximum and minimum queue lengths, respectively, and investigated the impact of ABR parameters on the queue length.

• The Research Journal of the Costume Culture
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• v.22 no.4
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• pp.543-554
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• 2014

The purpose of this study was to find whether hemline cycles exist and whether hemlines show greater within-year variability over time. Utilizing US Vogue data from 1950 to 2013 on hemline length of women's daywear, total 2102 day-dresses or skirts on full fashion pictures were analyzed. The skirt length was divided by the total length of figure in the picture which was measured from shoulder to ankle. Aggregated yearly means smoothed by means of three-point moving averages were used to provide a better indication of the long-term direction of movement of the hemline. Within-year hemline variability was smoothed by the way of three-point moving average as well. The data showed five cycles on hemline change processes. The first cycle took 21 years from 1950 to 1971, which was the longest period and had the biggest hemline changes. The second cycle was the shortest from 1971 to 1977, in which hemline moved between below-knee length and midcalf. The hemline in the third cycle moved between midcalf and miniskirt. The third cycle took 16 years from 1977 to 1993. The forth was a short cycle from 1998 to 2001, and hemlines moved moderately between below-knee length and above-knee length. The fifth cycle has been on going since 2001, and the hemline has been getting longer after 2007. The within-year variability of hemlines was bigger in 1980s than previous years and was steadily increased.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1579-1586
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• 2020

Dissimilar metal joints (DMJs) are more common in the application of piping system of many industries. A 2- D and 3-D finite element analysis (FEA) is carried out on dissimilar metal Single Edged Notch Bending (DMSENB) specimens fabricated from ferritic steel, austenitic steel and Inconel - 182 alloy to study the behavior of DMJs with constraints by using linear elastic fracture mechanics (LEFM) principles. Studies on DMSENB specimens are conducted with respect to (i) dissimilar metal joint width (DMJW) (geometrical constraints) (5 mm, 10 mm, 20 mm, 30 mm and 50 mm) (ii) strength mismatch (material constraints) and (iii) crack lengths (16 mm, 20 mm and 24 mm) to study the DMJ behavior. From the FEA investigation, it is observed that (i) SIF increases with increase of crack length and DMJWs (ii) significant constraint effect (geometry, crack tip and strength mismatch) is observed for DMJWs of 5 mm and 10 mm (iii) stress distribution at the interfaces of DMSENB specimen exhibits clear indication of strength mismatch (iv) 3-D FEA yields realistic behavior (v) constraint effect is found to be significant if DMJW is less than 20 mm and the ratio of specimen length to the DMJW is greater than 7.4.

• Journal of Environmental Impact Assessment
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• v.23 no.2
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• pp.137-149
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• 2014

The purpose of this study is to investigate the dynamics of the Zacco platypus population among streams in the Gongjicheon water system, Korea from December 2010 to October 2011. In this study, fish fauna was collected 27 Species belonged to 9 Families. The legal protection species, such as a natural monument and endangered species was not collected. Korean endemic species was collected 6 species including to Z. koreanus. The ratio of Korean endemic species was 22.6%, and it was lower than 51.3% that average of Korean endemic species in the Hangang water system. About these status, we considered that Gongjicheon water system had lost of the unique characteristics of the Hangang water system by the anthropogenic disturbances. The result of analysis to length-weight relationship and condition factor(K) of Z. platypus population in the Gongjicheon water system, the regression coefficient value(b) to indication of growth degree of the population was 3.04 and the slope of the condition factor(K) to indication of corpulency had positive value, respectively. These results seems to be that the Z. platypus population is maintained to a little unstably. In addition, the values of the degree of growth and corpulence were very low than the other natural streams in the Hangang water system, so it considered that the many artificially stress factors are occurred in this study area. These results are similar to Fish Assessment Index(FAI) in the assessment for health of aquatic ecosystem. Therefore, we are considered to require precise investigation and sustained monitoring for the restorations of stream ecosystem in the Gongjicheon water system.

• Journal of Korean Foot and Ankle Society
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• v.12 no.1
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• pp.36-40
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• 2008

Purpose: The purpose of this study is to find out the normal results in ankle on varus stress, valgus stress, and anterior draw stress in young men in korea. This would be helpful as the basic data of measuring of ankle instability for operational indication. Materials and Methods: Varus and Valgus stress anteroposterior radiographs and Anterior drawing stress lateral radiographs of 600 normal ankles were reviewed. First, A line parallel was drawn parallel to the articular surface of the distal tibia, and another line was drawn parallel to the articular surface of the talus on anteroposterior radiographs. The interior angle that subtended by these two lines was measured. Second, the reference point is located at the posterior border of the tibia, and the shortest distance from this point to the proximal posterior articular surface of the talus is measured. Results: There were 300 males and 600 ankles. The mean age overall was 21 years (19-22 years) old. The mean length of ankle on anterior draw stress was $5.54{\pm}3.33\;mm$. The mean a interior angle of ankle on varus stress was $0^{\circ}-8.93^{\circ}$, and on valgus stress $0^{\circ}-7.78^{\circ}$. Conclusion: We can consider for operational indication at over the 8.87 mm on anterior draw stress, over the $8.93^{\circ}$ on varus stress, and over the $7.78^{\circ}$ on valgus.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.1
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• pp.43-53
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• 1996

Numerical simulation was performed for the 3-dimensional flow filed of gas and particle phase for cyclone dust collector. FVM(Finite Volume Method) was employed for gas phase. The flow was solved suing the k-.varepsilon. epsilon turbulence model. The particle exit at the bottom of the cone was treated as a solid wall in this model because the gas flow through the effective dust exit is usually insignificant. The major parameters considered in this study was vortex finder diameter, effective dust exit diameterm vortex finder length, inlet type for dimension performance. Particle trajectory calculations were made for three different, particle sizes of 1, 25 and 50 .mu.m. The results obtained from this study give some physical insight of dust particle collection mechanism together with the indication of the collection efficiency. The simulation results were in generally good agreement with empirical knowledge. The application of this kind of computer program looks promising as a potential tool for the design of cyclone and determination of optimum operating condition.

• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.3
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• pp.57-63
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• 1992

The present investigation was undertaken to determine if CO2 enrichment promoted rooting and subsequent growth of Lagerstroemia indica L. cuttings. Cutting were taken from the one-year-old semihardwood twigs, and rooted in enclosed propagation frame with enriched CO2 levels (500-2000ppm) regulated by a gas monitor. The base of each cutting was dippid from 500 to 4000ppm naphthalenacetic acid. Roothing was determined after 3 months. CO2 enrichment during roothing increased the rooting percentage and number of roots per cutting, but nontreated cuttings rooted in low percentages producing one or two roots. The length of new shoots and dry weight of whole cuttings in CO2 enrichment were significantly greater than those of the atmospheric controls. The organic and inorganic compounds concentraion were measured as an indication of nutritional state in whole cuttings. As a result of CO2 enrichment, carbohydrate, protein and inorganic compounds(total nitrogen, P2O5, K2O, CaO, MgO) concentration were higher than controls.

• Magazine of the Korean Society of Agricultural Engineers
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• v.19 no.1
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• pp.4296-4311
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• 1977

This study was conducted to derive an Instantaneous Unit Hydrograph for the accurate and reliable unitgraph which can be used to the estimation and control of flood for the development of agricultural water resources and rational design of hydraulic structures. Eight small watersheds were selected as studying basins from Han, Geum, Nakdong, Yeongsan and Inchon River systems which may be considered as a main river systems in Korea. The area of small watersheds are within the range of 85 to 470$\textrm{km}^2$. It is to derive an accurate Instantaneous Unit Hydrograph under the condition of having a short duration of heavy rain and uniform rainfall intensity with the basic and reliable data of rainfall records, pluviographs, records of river stages and of the main river systems mentioned above. Investigation was carried out for the relations between measurable unitgraph and watershed characteristics such as watershed area, A, river length L, and centroid distance of the watershed area, Lca. Especially, this study laid emphasis on the derivation and application of Instantaneous Unit Hydrograph (IUH) by applying Nash's conceptual model and by using an electronic computer. I U H by Nash's conceptual model and I U H by flood routing which can be applied to the ungaged small watersheds were derived and compared with each other to the observed unitgraph. 1 U H for each small watersheds can be solved by using an electronic computer. The results summarized for these studies are as follows; 1. Distribution of uniform rainfall intensity appears in the analysis for the temporal rainfall pattern of selected heavy rainfall event. 2. Mean value of recession constants, Kl, is 0.931 in all watersheds observed. 3. Time to peak discharge, Tp, occurs at the position of 0.02 Tb, base length of hlrdrograph with an indication of lower value than that in larger watersheds. 4. Peak discharge, Qp, in relation to the watershed area, A, and effective rainfall, R, is found to be {{{{ { Q}_{ p} = { 0.895} over { { A}^{0.145 } } }}}} AR having high significance of correlation coefficient, 0.927, between peak discharge, Qp, and effective rainfall, R. Design chart for the peak discharge (refer to Fig. 15) with watershed area and effective rainfall was established by the author. 5. The mean slopes of main streams within the range of 1.46 meters per kilometer to 13.6 meter per kilometer. These indicate higher slopes in the small watersheds than those in larger watersheds. Lengths of main streams are within the range of 9.4 kilometer to 41.75 kilometer, which can be regarded as a short distance. It is remarkable thing that the time of flood concentration was more rapid in the small watersheds than that in the other larger watersheds. 6. Length of main stream, L, in relation to the watershed area, A, is found to be L=2.044A0.48 having a high significance of correlation coefficient, 0.968. 7. Watershed lag, Lg, in hrs in relation to the watershed area, A, and length of main stream, L, was derived as Lg=3.228 A0.904 L-1.293 with a high significance. On the other hand, It was found that watershed lag, Lg, could also be expressed as {{{{Lg=0.247 { ( { LLca} over { SQRT { S} } )}^{ 0.604} }}}} in connection with the product of main stream length and the centroid length of the basin of the watershed area, LLca which could be expressed as a measure of the shape and the size of the watershed with the slopes except watershed area, A. But the latter showed a lower correlation than that of the former in the significance test. Therefore, it can be concluded that watershed lag, Lg, is more closely related with the such watersheds characteristics as watershed area and length of main stream in the small watersheds. Empirical formula for the peak discharge per unit area, qp, ㎥/sec/$\textrm{km}^2$, was derived as qp=10-0.389-0.0424Lg with a high significance, r=0.91. This indicates that the peak discharge per unit area of the unitgraph is in inverse proportion to the watershed lag time. 8. The base length of the unitgraph, Tb, in connection with the watershed lag, Lg, was extra.essed as {{{{ { T}_{ b} =1.14+0.564( { Lg} over {24 } )}}}} which has defined with a high significance. 9. For the derivation of IUH by applying linear conceptual model, the storage constant, K, with the length of main stream, L, and slopes, S, was adopted as {{{{K=0.1197( {L } over { SQRT {S } } )}}}} with a highly significant correlation coefficient, 0.90. Gamma function argument, N, derived with such watershed characteristics as watershed area, A, river length, L, centroid distance of the basin of the watershed area, Lca, and slopes, S, was found to be N=49.2 A1.481L-2.202 Lca-1.297 S-0.112 with a high significance having the F value, 4.83, through analysis of variance. 10. According to the linear conceptual model, Formular established in relation to the time distribution, Peak discharge and time to peak discharge for instantaneous Unit Hydrograph when unit effective rainfall of unitgraph and dimension of watershed area are applied as 10mm, and $\textrm{km}^2$ respectively are as follows; Time distribution of IUH {{{{u(0, t)= { 2.78A} over {K GAMMA (N) } { e}^{-t/k } { (t.K)}^{N-1 } }}}} (㎥/sec) Peak discharge of IUH {{{{ {u(0, t) }_{max } = { 2.78A} over {K GAMMA (N) } { e}^{-(N-1) } { (N-1)}^{N-1 } }}}} (㎥/sec) Time to peak discharge of IUH tp=(N-1)K (hrs) 11. Through mathematical analysis in the recession curve of Hydrograph, It was confirmed that empirical formula of Gamma function argument, N, had connection with recession constant, Kl, peak discharge, QP, and time to peak discharge, tp, as {{{{{ K'} over { { t}_{ p} } = { 1} over {N-1 } - { ln { t} over { { t}_{p } } } over {ln { Q} over { { Q}_{p } } } }}}} where {{{{K'= { 1} over { { lnK}_{1 } } }}}} 12. Linking the two, empirical formulars for storage constant, K, and Gamma function argument, N, into closer relations with each other, derivation of unit hydrograph for the ungaged small watersheds can be established by having formulars for the time distribution and peak discharge of IUH as follows. Time distribution of IUH u(0, t)=23.2 A L-1S1/2 F(N, K, t) (㎥/sec) where {{{{F(N, K, t)= { { e}^{-t/k } { (t/K)}^{N-1 } } over { GAMMA (N) } }}}} Peak discharge of IUH) u(0, t)max=23.2 A L-1S1/2 F(N) (㎥/sec) where {{{{F(N)= { { e}^{-(N-1) } { (N-1)}^{N-1 } } over { GAMMA (N) } }}}} 13. The base length of the Time-Area Diagram for the IUH was given by {{{{C=0.778 { ( { LLca} over { SQRT { S} } )}^{0.423 } }}}} with correlation coefficient, 0.85, which has an indication of the relations to the length of main stream, L, centroid distance of the basin of the watershed area, Lca, and slopes, S. 14. Relative errors in the peak discharge of the IUH by using linear conceptual model and IUH by routing showed to be 2.5 and 16.9 percent respectively to the peak of observed unitgraph. Therefore, it confirmed that the accuracy of IUH using linear conceptual model was approaching more closely to the observed unitgraph than that of the flood routing in the small watersheds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.105-115
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• 2004

Growth pattern of the soft clam (Mya arenaria oonogei) was estimated based on samples collected from the Yeongsan River estuary on the southwest coast of Korea between August 1996 and September 1997. Mean density of the clam during study period was $55\;ind./m^2$ and varied monthly from 281 to $8\;ind./m^2.$ The clams from the study area ranged in age from one year to seven years, with shell lengths between 40.4 mm and 104.1 mm and biomass between 8.4 and 152.3 g in total wet weight. The spawing season was estimated to occur between September and October based upon a reduced fatness index, an indication of spawning, during these months. Burial depths increased with growth of the clams and most were found buried between 10 and 20 cm in the sediments. Significant relationships were found between shell length and shell height (SH), total wet weight, (TWt), meat wet weight (MWt), meat dry weight (DWt), ash free dry weight (AFDW) and burial depth. The von Bertalanffy growth equations of the clams were $L_t(mm)=138.98(1-e^{-0.1325(t+0.8853)})\;and\;W_t\;(gTWt)=325.93\;(1-e^{0.1325(t+0.8853)})^{2.6982}.$ These equations suggest that in their first year the clams should reach 31 mm in length with a biomass of 5.7 g in total wet weight.