• Title/Summary/Keyword: Group testing

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Investigating the Moderating Impact of Hedonism on Online Consumer Behavior (탐색쾌악주의대망상소비자행위적조절작용(探索快乐主义对网上消费者行为的调节作用))

  • Mazaheri, Ebrahim;Richard, Marie-Odile;Laroche, Michel
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.123-134
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    • 2010
  • Considering the benefits for both consumers and suppliers, firms are taking advantage of the Internet as a medium to communicate with and sell products to their consumers. This trend makes the online shopping environment a growing field for both researchers and practitioners. This paper contributes by testing a model of online consumer behavior with websites varying in levels of hedonism. Unlike past studies, we included all three types of emotions (arousal, pleasure, and dominance) and flow into the model. In this study, we assumed that website interfaces, such as background colors, music, and fonts impact the three types of emotions at the initial exposure to the site (Mazaheri, Richard, and Laroche, 2011). In turn, these emotions influence flow and consumers' perceptions of the site atmospherics-perception of site informativeness, effectiveness, and entertainment. This assumption is consistent with Zajonc (1980) who argued that affective reactions are independent of perceptual and cognitive operations and can influence responses. We, then, propose that the perceptions of site atmospherics along with flow, influence customers' attitudes toward the website and toward the product, site involvement, and purchase intentions. In addition, we studied the moderating impact of the level of hedonism of websites on all the relationship in the model. Thus, the path coefficients were compared between "high" and "low" hedonic websites. We used 39 real websites from 12 product categories (8 services and 4 physical goods) to test the model. Among them, 20 were perceived as high hedonic and 19 as low hedonic by the respondents. The result of EQS 6.1 support the overall model: $\chi^2$=1787 (df=504), CFI=.994; RMSEA=.031. All the hypotheses were significant. In addition, the results of multi-groups analyses reveal several non-invariant structural paths between high and low hedonic website groups. The findings supported the model regarding the influence of the three types of emotions on customers' perceptions of site atmospherics, flow, and other customer behavior variables. It was found that pleasure strongly influenced site attitudes and perceptions of site entertainment. Arousal positively impacted the other two types of emotions, perceptions of site informativeness, and site involvement. Additionally, the influence of arousal on flow was found to be highly significant. The results suggested a strong association between dominance and customers' perceptions of site effectiveness. Dominance was also found to be associated with site attitudes and flow. Moreover, the findings suggested that site involvement and attitudes toward the product are the most important antecedents of purchase intentions. Site informativeness and flow also significantly influenced purchase intentions. The results of multi-group analysis supported the moderating impacts of hedonism of the websites. Compared to low (high) hedonic sites, the impacts of utilitarian (hedonic) attributes on other variables were stronger in high (low) hedonic websites. Among the three types of emotions, dominance (controlling feelings) effects were stronger in high hedonic sites and pleasure effects were stronger in low hedonic sites. Moreover, the impact of site informativeness was stronger for high hedonic websites compared to their low-hedonic counterparts. On the other hand, the influence of effectiveness of information on perceptions of site informativeness and the impact of site involvement on product attitudes were stronger for low hedonic websites than for high hedonic ones.

Studies on the Antioxioative Character in the Etnyl Acetate Extractions of Rumex crispus (Rumex crispus의 에칠아세테이트 추출물의 항산화 성분에 관한 연구)

  • 신춘혜
    • KSBB Journal
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    • v.16 no.6
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    • pp.592-602
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    • 2001
  • This study was undertaken to investigate the antioxidative substance and activity of ethyl acetate extracted from Rumex crispus. Sample extracted follow in proper course of a solvent. Material refinement was carried out using silicagel column and Sephadex LH-20 column chromatography. Material sorting was carried by Gas Chromatography(GC/MS). 1,1-Diphenyl-2-Picrylhydrazyl(DPPH) free radical scavenging and enzyme activity were measured for antioxidative activity. as result of testing by DPPH free radical scavenging activity, Antioxidative activity was shown as the highest in the root, then leaf and stem in order. Ethyl acetate extraction of root part were 50% inhibitory concentration (IC50) Rumex activty(6.1 ug/mL). Rumex nipponicus(9.8 ug/ml) and Rumex acetoceae(31.5 ug/mL) in leaf part. The highest antioxidative activity of sample refined through silicagel column chromatography of Rumex crispus was appealed Fraction 5(IC50;3.57 ug/mL) in root and Fraction 6(IC50;85.9 ug/mL) in leaf. Fraction 5 in roof & Fraction 6 in leaf were refined using Sephadex LH-20 column chromatography. The highest antioxidative activity were appeared Fraction 4 (IC50;3.57 ug/mL) and Fraction 4 (IC50;18.41 ug/mL)in leaf. As for main phenol compounds 2,6-Dichloro-4-nitropnenol and 2-Isopropyl-5-methyl Phenol were identified in root and leaf, While 4-Vinyl-2- methoxy-phenol and 2,3-Dihydro- benzofuran were identifica ted only in leaf. Enzyme activity was shown low both in peroxidase(PDD) Non-activate(IU/mg protein)and in Superoxide dismutase(SOD) non-activate(IU/mg protein). 2,6-Dichloro-4-nitrophenol, 2-Isopropyl-5-methyl phenol, 4-Vinyl-2-methoxy-phenol were obtained in this experiment and these compounds are phenolic compounds which have OH group in the structure. With the result of this study these phenolic compounds which are extracted from Rumex crispus have high antioxidative effect. This antioxidative effect of Rumex crispus can be applied for chromo-preventive and antioxidative supplements which can be used for anti-allegy, aging, anti-tumor, aging and other oxidative disease for health promotion.

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Early Identification of Gifted Young Children and Dynamic assessment (유아 영재의 판별과 역동적 평가)

  • 장영숙
    • Journal of Gifted/Talented Education
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    • v.11 no.3
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    • pp.131-153
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    • 2001
  • The importance of identifying gifted children during early childhood is becoming recognized. Nonetheless, most researchers preferred to study the primary and secondary levels where children are already and more clearly demonstrating what talents they have, and where more reliable predictions of gifted may be made. Comparatively lisle work has been done in this area. When we identify giftedness during early childhood, we have to consider the potential of the young children rather than on actual achievement. Giftedness during early childhood is still developing and less stable than that of older children and this prevents us from making firm and accurate predictions based on children's actual achievement. Dynamic assessment, based on Vygotsky's concept of the zone of proximal development(ZPD), suggests a new idea in the way the gifted young children are identified. In light of dynamic assessment, for identifying the potential giftedness of young children. we need to involve measuring both unassisted and assisted performance. Dynamic assessment usually consists of a test-intervene-retest format that focuses attention on the improvement in child performance when an adult provides mediated assistance on how to master the testing task. The advantages of the dynamic assessment are as follows: First, the dynamic assessment approach can provide a useful means for assessing young gifted child who have not demonstrated high ability on traditional identification method. Second, the dynamic assessment approach can assess the learning process of young children. Third, the dynamic assessment can lead an individualized education by the early identification of young gifted children. Fourth, the dynamic assessment can be a more accurate predictor of potential by linking diagnosis and instruction. Thus, it can make us provide an educational treatment effectively for young gifted children.

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Long-term Changes in Soil Chemical Properties in Organic Arable Farming Systems in Korea (작물의 지속적인 유기 재배가 토양의 이화학적 특성변화에 미치는 영향)

  • Lee, Yun-Jeong;Choe, Du-Hoi;Kim, Seung-Hwan;Lee, Sang-Min;Lee, Yong-Hwan;Lee, Byung-Mo;Kim, Tae-Wan
    • Korean Journal of Soil Science and Fertilizer
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    • v.37 no.4
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    • pp.228-234
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    • 2004
  • In organic farming, nutrients for the crop production are mostly supplied by compost containing various organic materials. The long-term organic cultivation would result in continuous changes of soil chemical properties and fertility. The aim of this study was to investigate the contribution of long-term organic cultivation to the soil fertility in Korea focusing on the chemical properties of soil. Soil samples were collected from organic farms that had been cultivated for 8-10 years after certification of organic product through the conversion periods of 2-3 years. Thereby each organic farm had acquired optimal cultivating techniques and soil condition. We separated organic farms into three groups by cultivating crops, i.e. leaf vegetables, fruit vegetables and fruit trees. In each group, five representative farms were chosen in order to investigate the relationships between application rate of compost and nutrient contents in soil. The application rate of compost was approximately $10-15Mg\;10a^{-1}$ for the first 2-3 years at the beginning of organic farming and then reduced to a rate of $3-4Mg\;10a^{-1}$ after stabilization of organic matter content in soil with $30-50g\;10a^{-1}$. However, the continuous organic farming for 8-10 years resulted in accumulation of nutrients, especially of P, in soil probably due to the excessive amounts of compost applied. In conclusion, we suggest that the application rate and organic sources of compost should be decided on the basis of P content in soil by soil testing and thereafter the lack of soil N content for crop cultivation should be compensated by crop rotation with such as legumes. This might be an approach to the original meaning of organic farming as an environmental friendly agriculture.

A Study on Shear Bond Strength of Core-veneer Interface for Bilayered all Ceramics (Bilayered all Ceramics에서 Core와 Veneer 계면의 전단결합강도에 관한 연구)

  • Jung, Yong-Su;Lee, Jin-Han;Lee, Jae-In;Dong, Jin-Keun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.3
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    • pp.231-242
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    • 2008
  • Purpose: The purpose of this study was to investigate the bond strength of the core-veneer interface in all ceramic systems. Material and Methods: The all ceramic systems tested with their respective veneer were IPS Empress 2 with IPS Eris, IPS e.max Press with IPS e.max Ceram and IPS-e.max ZirCAD with IPS e.max Ceram. Cores (N=36, N=12/group, diameter: 10mm, thickness: 3mm) were fabricated according to the manufacturer's instruction and cleaned with ultrasonic cleaner. The veneer(diameter: 3mm, thickness: 2mm) were condensed in stainless steel mold and fired on to the core materials. After firing, they were again ultrasonically cleaned and embedded in acrylic resin. The specimens were stored in distilled water at $37^{\circ}C$ for 1 week. The specimens were placed in a mounting jig and subjected to shear force in a universal testing machine(Z020, Zwick, Germany). Load was applied at close to the core-veneer interface as possible with crosshead speed of 1.00mm/min until failure. Average shear bond strengths(MPa) were analyzed with a one-way analysis of variance and the Tukey test(${\alpha}=.05$). The failed specimens were examinated by scanning electron microscopy(JSM-6360, JEOL, Japan). The pattern of failure was classified as cohesive in core, cohesive in veneer, mixed or adhesive. Results: The mean shear bond strength($MPa{\pm}SD$) were IPS e.max Press $32.85{\pm}6.75MPa$, IPS Empress 2 $29.30{\pm}6.51MPa$, IPS e.max ZirCAD $28.10{\pm}4.28MPa$. IPS Empress 2, IPS e.max Press, IPS e.max ZirCAD were not significantly different from each others. Scanning electron microscopy examination revealed that adhesive failure did not occur in any all ceramic systems. IPS Empress 2 and IPS e.max Press exhibited cohesive failure in both the core and the veneer. IPS e.max ZirCAD exhibited cohesive failure in veneer and mixed failure.

Assessment of the Effectiveness of Biofeedback Therapy in Children with Pelvic Floor Dyssynergia (소아 골반저 근실조에서 바이오피드백 치료의 유용성)

  • Park, Kie-Young;Chang, Soo-Hee;Kim, Kyung-Mo
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.10 no.1
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    • pp.51-59
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    • 2007
  • Purpose: Recently well-developed anorectal function tests have revealed that there is an obvious pelvic floor dyssynergia (PFD) pattern in pediatric patients with constipation, as well as in adult's. The use of biofeedback therapy (BT) has been widely implemented in adult PFD patients; however, this approach has only rarely been considered for pediatric PFD patients. Therefore, we assessed the effectiveness of BT in children with PFD. Methods: We studied 70 children with PFD, who were referred to the department of pediatrics at the Asan Medical Center for the management of soiling or chronic constipation from September 2002 to February 2005. Diagnosis of PFD and assessment of the efficacy of BT for PFD treatment were carried out along with several ano-rectal function tests (cine-defecography, ano-rectal manometry, balloon expulsion test and intra-anal EMG); in addition, a questionnaire was administered. The BT based intra-anal EMG was performed. A follow-up telephone interview was performed more than 6 months later. Results: Most of the symptoms and results of the ano-rectal function tests were statistically improved after BT. In comparisons between the BT and control groups (BT refusal group due to poor compliance), the symptoms were statistically improved at follow-up. Therefore, for the shortterm improvement of symptoms, BT was better than conservative therapy alone. The negative feelings associated with ano-rectal function testing and BT were directly associated with failure or success of therapy. Conclusion: Pediatric patients with constipation or soiling that presented with an obvious PFD pattern showed that BT was a useful therapeutic tool for rapid improvement of symptoms.

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An experimental study of the strength and internal structure of solder joint of fixed partial denture (가공의치(架工義齒) 납착부(蠟着部)의 강도(强度)와 내부구조(內部構造)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Park, Sang-Nam;Kay, Kee-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.23 no.1
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    • pp.39-59
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    • 1985
  • The purpose of this study was to investigate how gap distances of 0.13mm, 0.15mm, 0.20mm, and 0.30mm affects solder joint strength from gold alloys and nickel-chromium base alloys and to examine the composition of solder gold, the solder joint of gold alloys and nickel-chromium base alloys. The tensile test specimens were prepared in the split stainless steel mold with a half dumbbell shape 2.5mm in diameter and l2mm in length. 6 pairs of specimens of each gap distance group of gold alloys and nickel-chromium base alloys were made and 48 pairs of all specimens were soldered with solder gold of 666 fineness. All soldered specimens were machined to a uniform diameter and then a tensile load was applied at a cross-head speed of 0.10mm/min using Instron Universal Testing Machine, Model 1115. The fractured specimens at solder gold of solder joint fracture with each gap distance of 0.13mm, 0.15mm, 0.20mm, and 0.30mm were examined under the Scanning Electron Microscope, JSM-35c and the composition of solder gold, the solder joint of gold alloys and nickel-chromium base alloys was analyzed by Electron Probe Micro Analyzer. The results of this study were obtained as follows: 1. In case of soldering of gold alloys, the tensile strength between gold alloys showed $37.33{\pm}2.52kg/mm^2$ at 0.13, $39.14{\pm}3.35kg/mm^2$ at 0.15mm, $43.76{\pm}2.97kg/mm^2$ at 0.20mm, and $49.18{\pm}4.60kg/mm^2$ at 0.30mm. There was statistically significant difference at each gap distance, and so the greater increase of gap distance showed the greater tensile strength. 2. In case of soldering of nickel-chromium base alloys, the tensile strength between nickel-chromium base alloys showed $34.84{\pm}4.26kg/mm^2$ at 0.13mm, $37.25{\pm}2.49kg/mm^2$ at 0.15mm, $42.91{\pm}4.32kg/mm^2$ at 0.20mm, and $46.93{\pm}4.21kg/mm^2$ at 0.30mm. There was not statistically significant difference only between 0.13mm and 0.15mm and bet ween 0.20 mm and 0.30mm, but generally the greater increase of gap distance showed the greater tensile strength. 3. The greater increase of gap distance shoed less porosities in solder gold at solder joint fracture. 4. In solder gold Au, Cu, Ag, Zn, and Sn were composed and Au and Cu were mostly distributed uniformly. 5. In solder joints of solder gold and gold alloys Au, Cu, Ag, Zn, and Sn were composed in solder gold and Au, Cu, Ag, Pt, and Pd were composed in gold alloys. Au and Cu of solder gold and gold alloys were mostly distributed uniformly and the diffusion of other elements except Pt and Pd around the solder joint was not almost found. In solder joints of solder gold and nickel-chromium base alloys Au, Cu, Ag, Zn, and Sn were composed in solder gold and Ni, Cr, and Al were composed in nickel-chromium base alloys. Au and Cu of solder gold and Ni and Cr of nickel-chromium base alloys were mostly distributed uniformly and the diffusion of other elements except Cr around the solder joint was not almost found.

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Effect of universal primer on shear bond strength between resin cement and restorative materials (다용도 프라이머가 레진 시멘트와 수복재의 전단 결합 강도에 미치는 영향)

  • Kim, Na-Hong;Shim, June-Sung;Moon, Hong-Suk;Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.50 no.2
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    • pp.112-118
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    • 2012
  • Purpose: The purpose of this study was to evaluate the difference in shear bonding strength between resin cements to dental materials when a universal primer (Monobond plus) was applied in place of a conventional primer. Materials and methods: Four groups of testing materials: gold alloy (Argedent Euro, n = 16), non precious metal (T-4, n = 20), zirconia (Cercon, n = 20) and glass ceramic (IPS e.max press, n = 20), were fabricated into discs, which were embedded in an acrylic resin matrix. The gold alloy specimens were airborne-particle abraded, 8 of the specimens were coated with Metal primer II, while the remaining 8 specimens were coated with Monobond plus. The non precious and zirconia specimen were airborne-particle abraded then, the control group received Alloy primer coating, while the other was coated with Monobond plus. Glass ceramic specimens were etched. 10 specimens were coated with Monobond-S and the remaining specimens were coated using Monobond plus. On top of the surface, Multilink N was polymerized in a disc shape. All of the specimens were thermal cycled before the shear bonding strength was measured. Statistical analysis was done with Two sample $t$-test or Mann-Whitney U test (${\alpha}$=.05). Results: There were no significant differences in bonding strength depending on the type of primer used in the gold alloy and glass ceramic groups ($P$>.05), however, the bonding strengths of resin cements to non precious metal and zirconia groups, were significantly higher when the alloy primer was used ($P$<.05). Conclusion: Within the limitations of this study, improvement of universal primers which can be applied to all types of restorations is recommended to precious metals and zirconia ceramics. But, the bond strengths of non precious metals and zirconia ceramics were significantly lower when compared to a 10-MDP primer. More research is needed to apply universal primers to all types of restorations.

A Feasibility Study for Decision-Making Support of a Radioactive Contamination Model in an Urban Environment (METRO-K) (도시환경 방사능오염 평가모델 METRO-K의 대응행위 결정지원을 위한 실용성 연구)

  • Hwang, Won-Tae;Han, Moon-Hee;Jeong, Hyo-Joon;Kim, Eun-Han;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
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    • v.33 no.1
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    • pp.27-34
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    • 2008
  • A Korean urban contamination model METRO-K (${\underline{M}}odel$ for ${\underline{E}}stimates$ the ${\underline{T}}ransient$ Behavior of ${\underline{R}}adi{\underline{O}}active$ Materials in the ${\underline{K}}orean$ Urban Environment, which is capable of calculating the exposure doses resulting from radioactive contamination in an urban environment, is taking part in a model testing program EMRAS (${\underline{E}}nvironmental$ ${\underline{M}}odelling$ for ${\underline{RA}}diation$ ${\underline{S}}afety$) oragnized by the IAEA (${\underline{I}}nternational$ ${\underline{A}}tomic$ ${\underline{E}}nergy$ ${\underline{A}}gency$). For radioactive contamination scenarios of Pripyat districts and a hypothetical RDD (${\underline{R}}adiological$ ${\underline{D}}ispersal$ ${\underline{D}}evice$), the predicted results using METRO-K were submitted to the EMRAS's Urban Contamination Working Group. In this paper, the predicted results for the contamination scenarios of a Pripyat district were shown in case of both without remediation measures and with ones. Comparing with the predictied results of the models that have taken part in EMRAS program, a feasibility for decision-making support of METRO-K was investigated. As a predicted result of METRO-K, to take immediately remediation measures following a radioactive contamination, if possible, might be one of the best ways to reduce exposure dose. It was found that the discrepancies of predicted results among the models are resulted from 1) modeling approaches and applied parameter values, 2) exposure pathways which are considered in models, 3) assumptions of assessor such as contamination surfaces which might affect to an exposure receptor and their sizes, 4) parameter values which are related with remediation measures applied through literature survey. It was indentified that a Korean urban contamination model METRO-K is a useful tool for dicision-making support through the participation of EMRAS program.

Combination Culture of Rotifer Brachionus rotundiformis and Copepod Apocylops sp. (로티퍼 Brachionus rotundiformis와 코페포다 Apocyclops sp.의 혼합 배양)

  • Jung, Min-Min;Rho, Sum
    • Journal of Aquaculture
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    • v.11 no.4
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    • pp.449-455
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    • 1998
  • The small size food organism(under the size 150${\mu}m$) is needed as food for early stage of marine fish larvae of small mouse (e.g the group of grouper). This study was investigated to develop a method for copepod Apocyclops sp. culture in combination with the rotifer B. rachionus for stable culture of copepod species and harvest of various size food organisms. The culture conditions as temperature, salinity, culture volume, photo period, culture preiod and observation interval were 25${\circ}C$, 22ppt, 40ml, all dark except to observation time, 16 days and every two day during the experimental period, respectively. The Tetraselmis suecica was used as the food for the two testing orgtanisms. After every two day counting, theses two organisms were transferred to fresh culture tanks with Tetraselmis suecica of $7{\times}10^5$cells/ml. In the mixed culture of B. rotundiformis and A. sp., growth of rotifer was suppressed by mixed culture with A. sp. whereas the growth of copepod Apocyclops was promoted in the mixed culture with rotifer B. rotundiformis (the maximum density was 22 individuals/ml through the 16 culture days). Moreover, the number of copepod nauplius were promoted about 2 times in the mixed culture compared to the numbers in single species culture. With this combination culture, the havested two food organisms of variable sizes. This size variation of food organisms was useful tools for larval rearing of small mouse marine fish larvae and next step food organism size of post hatched larvae.

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