• The Korean Journal of Malacology
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• v.31 no.1
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• pp.49-59
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• 2015

Eight species of the family Bithyniidae, Bithynia striatula, B. tentaculata, B. siamensis, B. leachi, B. kiusiuensis, B. misella, Bithynia sp. from Nepal, and Gabbia australis were studied for comparison of the radula structure by scanning electron microscope. Radular ribbons of B. siamensis and B. leachi had 60-70 rows, and the other species had 40-50 rows. Teeth of all species studied had symmetrical structure, i.e. a total of seven teeth (one central tooth, and one lateral and two pairs of marginal teeth on each side) in each row were observed. The basic tooth formula of eight bithyniids was 2:1:1:1:2. Numbers and shapes of cusps were slightly differ from individuals or species. The mesocone of the central tooth of B. striatula, B. tentaculata, B. siamensis and Bithynia sp. differed from those of the other species observed.

• Information Systems Review
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• v.8 no.1
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• pp.63-80
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• 2006

This paper suggests a normative performance measurement model for B2B e-marketplace. The model is for the neutral and systematic sourcing B2B e-marketplace. It is based on BSC that is very powerful and sound tool among all the available performance measurement systems. In addition, we used AHP to make the model more structured and to draw weights of performance measures from experts. We derived main features and factors affecting performance of e-business companies and especially of B2B e-marketplaces based on literature. In order to make the model usefulness, we co-worked with some experts who are engaged in real Korean B2B e-marketplaces. They included venture capitalists, top managers of B2B e-marketplaces, and consultants. By their assistances, we could find important evaluating factors and define the hierarchical structure. After defining the hierarchical structure, the expert group decided weights of performance indicators through the designed questionnaires. The weight for each measure was calculated using geometric mean of the questionnaire response. We made the case studies of two real Korean B2B e-marketplaces to apply the suggested model with some adjustments. The results of the case studies were so satisfactory that the suggested performance measurement model for B2B e-marketplace is useful and applicable to the real world.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.509-522
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• 2008

한국산 가막사리속(Bidens L.)에 포함된 10분류군(8종 2변종)의 수과형태를 연구하기 위하여 입체현미경과 주사전자현미경을 이용하여 관찰하였다. 연구된 가막사리속에서 까끄라기를 제외한 수과의 크기는 $3.0-19.5{\times}0.7-2.6 mm$이다. 관모는2-4개의 까끄라기로 구성되어 있고, 까끄라기의 길이는 2.2-5.6 mm이다. 강모의 배열은 1-3열이었다. 수과의 다형화가 6개의 분류군(B. bipinnata, B. biternata, B. frondosa, B. parviflora, B. pilosa var. pilosa, B. tripartita var. tripartita)에서 확인되었다. 수과의 형태와 까끄라기의 수에 의해 4가지 유형으로 구분되었다. - Type A: 장타원형이고, 까끄라기 수는 2개(B. parviflora); Type B: 장타원형이고, 까끄라기 수는 3개 이상(B. bipinnata, B. biternata, B. pilosa var. pilosa, B. pilosa var. minor) Type C: 도란형이고, 까끄라기의 수는 2개(B. frondosa, B. radiata var. radiata, B. radiata var. pinnatifida, B. tripartita var. tripartita); Type D: 도란형이고, 까끄라기의 수는 3개 이상(B. cernua). 까끄라기의 강모 표면무늬는 3가지 즉 나선상, 평활상, 불규칙한 직선형으로 나타났다. 수과의 표면은 각피층이 발달한 다각형, 평활상 그리고 굴곡형으로 나타났다. 수과형질의 분류학적 적용에 대하여 간략하게 토의하였다. 수과형질을 바탕으로 한국산 가막사리속 분류군에 대한 검색표를 제시하였다.

• Knowledge Management Research
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• v.23 no.3
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• pp.65-88
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• 2022

Companies actively engage with the public through social media to enhance sales and promote brand awareness, which was further encouraged by the pandemic. However, previous studies tend to consider companies as a group of identical features. This study focuses on the differences between B2B and B2C companies' social media content strategy in relation to user engagement. This study categorized KOSPI 100 companies that manage Facebook corporate fan pages into B2B and B2C, and then analyzed the contents they posted from January 1 to December 31, 2020. The result showed that B2C companies tended to use videos over images, prefer hashtags, and comment its product name more often compared to B2B companies. B2B companies preferred images, used more hyperlinks, and mentioned its company name more often. In B2B companies, images and length of text had positive effects on user engagement, while hyperlink and URL had negative effects. B2C companies' text length had positive effect on user engagement. This study provides practical implications to PR practitioners for establishing a social media strategy which enhances user engagement.

• Journal of Mushroom
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• v.22 no.1
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• pp.27-30
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• 2024

As a member of ectomycorrhizal fungi, Tricholoma matsutake has a symbiotic relationship with its host, Pinus densiflora. To cultivate T. matsutake artificially, the co-cultivation of T. matsutake mycelia and bacteria from shiro was introduced. In this study, bacteria were isolated from soil samples in Bonghwa-gun, and seven bacterial isolates (B22_7_B05, B22_7_B06, B22_7_B07, B22_7_B08, B22_7_B10, B22_7_B13, and B22_7_B14) promoted the growth of T. matsutake mycelia (147.48, 232.11, 266.72, 211.43, 175.17, 154.62, and 177.92%, respectively). Sequencing of the 16S rRNA region of the isolated bacteria was performed. B22_7_B05 and B22_7_B10 were identified as Bacillus toyonensis, B22_7_B06 and B22_7_B08 as Paenibacillus taichungensis, B22_7_B07 and B22_7_B14 as P. gorilla, and B22_7_B13 as P. odorifer. These bacterial isolates were associated with the shiro community and are expected to contribute to the cultivation of T. matsutake.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.179-186
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• 2003

This pot experiment was conducted to find out the effects of boron application( $B_{0}$ ) ; control, B$_1$; 0.2, $B_2$; 2.0, $B_3$; 6.0, $B_4$; 15.0 boron me/pot) on the forage performance of pure and mixed cultures of orchardgrass and white clover. The fourth part was concerned with the changes in the contents of B, Fe, Mn, Cu, and Zn in forages. The results obtained are summarized as follows: 1. The boron(B) contents of both forages and their differences among the B treatments generally decreased according to the cutting order. The B contents of white clover were somewhat lower in the $B_{0}$ than in the $B_2$. However, the differences in the yields between $B_{0}$ and $B_2$ were relatively great. It was probably caused by the latent B-deficiency in the $B_{0}$. Compared with white clover, the B contents of orchardgrass had relatively great differences between the $B_{0}$ and B$_2$, but both yields tended to be similar. 2. The contents of Fe, Mn, Cu, and Zn in both forages were generally different according to the forage species, whether it was a pure or mixed cultures, and additional fertilization. The effects of B application on their contents were different according to the micronutrients and above factors. 3. The Fe contents of white clover were lower in the $B_{0}$ and $B_4$ than in the$ B_2$. It tended to be related to the weak growth of roots and low yields in the $B_{0}$ and $B_2$. However, there were not consistent in the changes of contents of Mn, Cu, and Zn by the rates of B application. 4. The effects of B application on the total ion concentrations of Fe, Mn, Cu, and Zn were not consistent in both forages. However, the concentrations were generally affected by the changes in the contents of Mn and Zn. The concentrations of white clover were higher in a pure than in mixed culture.

• Korean Journal of Microbiology
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• v.17 no.4
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• pp.165-178
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• 1979

Phages of Lactobaciilus casei (PLC) isolated from plant drainage were classified and characterized. The results are as follows : 1. On the basis of host range pattern, phages could be divided into 2 groups (PLC-B and PLC-C). PLC-B group phages could be further divided into 5 sub-groups $(B_1, \;B_2, \;B_3, \;B_4, \;and\;B_5)$. Although PLC-C group phages had the same host range, they could be also divided into 2 sub-groups $(C_1\;and\;C_2)$ by morphlogical type. 2. It was $B_3$ group phages that represented a major proportion (44.4%) of phages tested. However, $B_1$ group phages were shown to have the widest host range. 3. Electron micrographs revealed that the phages fell into three different morphological types. $(B_1, \;B_2, \;and\;B_3)$ group phages hd a hexagonal head (52nm in diameter) and a sheathless noncontractile (245 nm in length). $B_4\;and\;C_2$ group phages had a hexagonal head (56 nm) and a short flexible tail (169nm) having no sheath. $B_5\;and\;C_1$ group phages were shown to have a hexagonal head (81 nm) and a contractile tail (140 nm) having a sheath, a base plate and tail fibers. 4. The inactivation of the phages by antisera indicated that serological relationships correlated completely with morphological types. 5. $B_1, \;C_1\;and\;C_2$ group phages produced a large (1, 2 mm in diameter) plaque with a clear ring. The morphology of plaques of $B_3\;and\;B_5$ group phages was the same as those produced by the above, but the average plaque sizes for $B_3\;and\;B_5$ were 0.8 mm abd 0.5 mm, respectively. $B_2\;and\;B_4$ group phages produced a small (0.5 mm) turbid plaque with an irregular edge. 6. The latent period and the average burst size of $B_1\;and\;B_3$ group phages were 90 min and 100, respectively. These phages reuqired calcium ions for their miltiplication. 7. $B_3$ group phages could not be absrobed to R-variant $KC_1$. 8. The order of resistance of phages to heat was $B_2\;>\;B_1, B_4\;and\;B_5\;>\;B_3\;and\;C_2, \;B_5$ group phages were more stable than $B_3$ in various pH values. $C_2$ group phages were more sensitive to UV irradiation than $B_1\;and\;B_3$ group phages. 9. Strains YIT9018 and IAM 1043 were induced by mitomycin C treatment. Phage particles detected in the lysates had a hexagonal head (38 and 49 nm, respectively), but no tail. Any sensitive indicator strain could not be isolated in spite of repaeated trials.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.2
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• pp.119-128
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• 2002

This study investigates dorsal aspect target strength with fish size, tilt angle and frequency characteristics for the schlegel's black rockfish(Sebastes achlegeli) and the red seabream (Pagrus major). This study was carried out on free swimming fish in a cage in order to obtain acoustic data of the biomass estimation using the scientific echo sounder. The results obtained from this study are summarized as follows; 1 The coefficients of the schlegel's black rockfish and the red seabream using maximum TS with fish length were expressed -63.7dB and -62.6dB at a frequency of 38kHz, -64.4dB and -65.4dB at 120kHz, and -62.4dB and -65.0dB at 200kHz, respectively. 2. The coefficients of the schlegel\`s black rockfish and the red seabream using averaged TS with fish length were expressed -68.4dB and -67.9dB at a frequency of 38kHz, -73.4dB and -72.7dB at 120kHz, and -70.BdE and -73.4dB at 2001Hs, respectively. 3. The coefficients of the schlegel's black rockfish and the red seabream using maximum TS with body weight were expressed -52.0dB and -50.9dB at a frequency of 38kHz, -52.7dB and -53.7dB at 120kHz, and -50.7dB and -53.3dB at 200kHz, respectively. 4. The coefficients of the schlegel's black rockfish and the red seabream using averaged TS with body weight were expressed -56.7dB and -56.2dB at a frequency of 38kHz, -61.7dB and -61.0dB at 120kHz, and -59.ldE and -61.6dB at 200kHz, respectively. 5. Varying the tiIt angle of the two red seabream from -26$^{\circ}$to +25$^{\circ}$, the variation width of target strength expressed smaller at a frequency of 38kHz than at 120kHz and expressed about 3~6dB higher head up than head down at 120kHz.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.1
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• pp.21-30
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• 1991

The estimation of the fish biomass density or the size of fish by means of the acoustic equipment is an important part in the quantitative assessment of fisheries resources. The precision of such estimates depend upon the target strength of fish and the accuracy to which the acoustic equipment has been calibrated. This paper examine the accuracy of the digital measurement system which is manufactured by way of trial in order to masure the target strength of fish, and calibrations of that system carry out with an ogive and a ellipsoid made of the aluminum and the epoxy, respectively. Furthermore, measurements of target strength for eight species of fish are made at 25, 50, 100 kHz. The accuracy of the digital measurement system is compared the theory with measurements on ogive and ellipsoid, and the agreement is reasonable. Result of establishments on the target strength to fish length and to fish weight regression obtained from the measurements are available to provide the methods of design for use in interpreting acoustic measurements of fish abundance on the experimented eight species.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.522-526
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• 2006

To investigate the effects of UV-B on fatty acid composition, lipid peroxidation and biochemical defense responses of plant, kidney bean (Phaseolus vulgaris L.) was subjected to enhanced UV-B irradiation [daily dose : 0.02.(No UV-B) and 11.36 (enhanced UV-B) $kJ\;m^{-2};UV-B_{BE}$] for 3 weeks. UV-B drastically inhibited both height and dry weight of kidney bean. The content of malondialdehyde significantly increased by about 50% after 3 weeks of UV-B irradiation. The ratio of unsaturated to saturated fatty acids of kidney bean was increased by UV-B irradiation. Three major polyamines of kidney bean leaves : putrescine, spermidine and spermine, were observed. All of the polyamine contents were increased with UV-B irradiation. These results suggested that enhanced UV-B radiation caused oxidative stress on lipids and biochemical protection responses might be activated to prevent from damaging effects of oxidative stress generated by UV-B irradiation.