• Journal of Korea Technology Innovation Society
• /
• v.10 no.1
• /
• pp.73-97
• /
• 2007

R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.4
• /
• pp.275-282
• /
• 1986

A series of studies on the properties of clayey terrace soils distributed at the inland (Yeongcheon) and coastal (Yeongjil) regions in Yeongnam district was carried out. On the base of the facts found and already reported about the macro morphological features as well as on pedological characters in micro scale, physicochemical properties, mineralogical characteristics etc., the present study dealt with soil genesis and tried to classify the soils for reasonable use and managements. 1. Although the both regions belonged to "Mesic" soil temperature regime and "red and yellow earths" areas of "Thornthwaite" pedo-climatic diagram, climatic indices as a soil forming factor indicate that the coastal Yeongil had milder than the inland Yeongcheon. 2. All the terrace soils had developed soil profiles with an "Argrllic B". Upyeong soils in Yeongil region had "Argillans" even in the "II B horizons" that possibly be "Paleo-argillic". 3. The bisequum profiles of Bancheon in Yeongcheon and Upyeong in Yeongil revealed that they were developed on Late Mesozoic shale and on semiconsolidated Tertiary deposits respectively, therefore the overlying clayey terrace deposits were assumed to be originated from the Early Quaternary deposits, Diluvium. 4. To supplement the Soil Taxonomy of USDA, the terrace soils with different degrees of gleyzation were classified as follows; Deogpyeong and Hwadong soils which have less than 50cm of paddified gley horizons (redness less than 0.5) in the upper part of the profiles by artificial surface irrigation, tentatively classified into "Anthrepiaquic Hapludalfs" and the Geugrag soils that have more than 50cm of paddified gley horizons within 1.2m of the profiles, into "Anthr-aquic Ochraqualfs" while the Upyeong soils that had greyish mottles in subsoils by natural ground water remain as an "Aquic Hapludalfs" the same as present. The Bancheon soils with free mottles are into "Typic Hapludalfs" as used at present.

• Journal of Embryo Transfer
• /
• v.19 no.1
• /
• pp.43-51
• /
• 2004

The present study was conducted to investigate the effects of fusion and/or activation protocol on in vitro development of porcine somatic cell nuclear transfer (SCNT) embryos. Porcine fetal fibroblast cells were transferred into the perivitelline space of enucleated in vitro matured oocytes. Cell fusion and activation were induced simultaneous fusion/activation (SA) or delayed activation (DA) with or without cytochalasin B (CB) treatment with electic pulses in 0.28 M mannitol-based medium. The SCNT embryos were cultured in vitro for 7 days and stained with Hoechst 33342 to determine the number of nuclei. After 7 days culture, cleavage and blastocyst formation rates were 72.4% and 7.6% in SCNT and 76.3% and 20.4% in parthenotes. To examine the effect of electric field strengths on development of SCNT embryos, oocytes were fused two pulses of 110 V/mm, 130 V/mm or 150 V/mm for 30 sec post-injection. The fusion and cleavage rates in 130 V/mm group (70.2% and 72.6%) and 150 V/mm group (72.6% and 70.5%) were higher (P<0.05) than 110 V/mm group (47.1% and 48.6%), respectively. However, the rate of embryos developing to the blastocyst stage (8.1%, 9.7% and 10.7%) were not different among three groups. The cleavage rates and the blastcyst formation rates were not different among three treatment groups (SA group, 71.4% and 9.7%; SA+CB treatment group, 74.7% and 8.0%; DA+CB treatment group, 70.8% and 11.2%, respectively). And, no different in the number of cells in blastocysts was observed among the three groups (22.5$\pm$12.8, 23.3$\pm$11.2 and 21.6$\pm$10.4, respectively). These result suggest that two pulses of 130 V/mm or 150 V/mm for 30 sec with SA treatment or DA treatment are enough for fusion/activation of porcine somatic cell nuclear transfer (SCNT) embryos to develop to the blastocyst stage.

• Korean Journal of Poultry Science
• /
• v.31 no.4
• /
• pp.283-291
• /
• 2004

Feeding trials were conducted with Euglena strains grown under different media. The effect of supplementation of Euglena on the laying performance, egg quality and fatty acid composition of egg yolk was studied. In experiment I, two hundred eighty 32-wk-old ISA Brown layers were randomly assigned to seven dietary treatments for 4 wks. Each treatment consisted of 4 replications with 10 birds each housed in two birds cages. Control diet was formulated to have $17\%$ CP and 2,750 kcal ME/kg. Euglena gracilis Z. (EG) was added to control diet at the level of 0.25, 0.5, $1.0\%$ and Euglena gracilis Z. bleached and DHA enriched (EGBD; a strain mutated by streptomycin and cultivated in DHA enriched medium) at the level of 0.5, 1.0, $2.0\%$ in the diet. In experiment 2, three hundred 84-wk-old ISA brown layers were randomly assigned to five dietary treatments: T1; Control, T2; T1 + EGBD $0.5\%$, T3; T1 + Euglena gracilis Z. DHA enriched (EGD; cultivated in DHA enriched medium) $0.5\%$, T4; T1 + EGD $1.0\%$, T5; T1 + EGD $2.0\%$. Each treatment had 5 replication of 12 birds each housed in two birds cages. In experiments 1 and 2, Euglena suppplementation did not significantly affect egg production but increased egg weight and feed intake. In experiment 1, EG was more effective in increasing egg yolk color score than EGBD. Egg yolk color of EG $1\%$ treatment showed the highest score. EGBD supplementation increased DHA concentration of egg yolk. EGBD $2\%$ treatment showed the highest DHA and the lowest palmitic and stearic acids concentration in the egg yolk. In experiment 2, EGBD $0.5\%$ treatment showed highest DHA level in egg yolk (P<0.05). It was conducted that EGBD is a single cell protein source rich in DHA, that can be used to produce DHA enriched eggs.

• Journal of Global Scholars of Marketing Science
• /
• v.19 no.2
• /
• pp.27-39
• /
• 2009

Compulsive consumption is regarded as a global phenomenon that can adversely affect consumer well-being. Although the topic has been studied in different cultural settings, we have seen relatively little theory development and explanations of compulsive behavior Nearly all previous empirical studies attempt to explain this behavior by correlating measures of compulsive behavior with independent variables taken within the same time frame. However, recent developments in social sciences suggest that such a phenomenon may best understood in the context of the person's earlier-in-life experiences. Using the life course paradigm as an overarching framework, the present research extends previous work on this topic. Following hypotheses were drawn from literature review: H1: The earlier in childhood and adolescence a person experiences family dislocation, the greater his or her likelihood of exhibiting compulsive behaviors in adulthood. H2: The earlier in life the young person experienced family dislocation, the greater the number of family disruption events the young person experienced prior entering adulthood years. H3: Family dislocation leads to (a) increased frequency of socio.oriented family communications and (b) decreased frequency of concept-oriented family communication. H4: Young adults who were raised in families characterized by a strong socio-oriented communication structure are more likely to exhibit compulsive consumption tendencies than those who were raised in families characterized by a weak socio-oriented family communication structure. H5: Young adults who were raised in families characterized by a strong concept-oriented communication structure are less likely to exhibit compulsive consumption tendencies than those who were raised in families characterized by a week concept-oriented family communication structure. H6: The relationship between family disruption events experienced during adolescence and perceived stressfulness of these events is moderated by (a) global family support, (b) emotional family support, and (c) material family support. Those reporting higher levels of family support as teenagers are less likely to report experiencing stress due to family disruption events. H7: Perceived stressfulness of family disruption events experienced during adolescent years are associated with compulsive consumption tendencies in early adulthood. H8: The greater the number of family disruption events young adults experienced during their adolescent years the more frequent was their communication about consumption with their peers. H9: The more frequent was the young persons' communication with their peers about consumption during their adolescent years, the more likely they are to report compulsive buying tendencies as young adults. We use a sample of 120 Thai undergraduate students attending classes taught in English as part of a four-year international program. Product-moment correlations, hierarchical regression analysis and partial correlation were used to analyze data. Results of testing hypotheses showed that hypothesis 2, 4, 7 and 9 were supported and hypothesis 1, 3, 5, 6 and 8 were not supported. Our study did not find a significant relationship between the age when a person experienced family dislocation and their compulsive behavior tendencies expressed as young adults. We did not find a significant relationship between family dislocation and family communication structures. But we found a significant positive relationship between socio-oriented communication structure and compulsive buying and a significant relationship between our peer communication and compulsive buying measures. Also we found perceived stressfulness due to the disruptive events to have a significant positive relationship between the perceived stressfulness and compulsive buying. Implications from these findings, limitations of this research and future research suggestions were discussed.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.4 no.2
• /
• pp.127-136
• /
• 1994

Diffusional sampling devices offer many advantages for measuring concentration levels of industrial contaminants than the conventional pump and charcoal tubes because they are lightweight, require no power, pump or tubing. This study designed to evaluate and compare the sampling performance of passive sampler to charcoal tube from mixed organic solvent workplace with 181 organic solvent using workers working in different concentration of organic solvents. All study workers kept both devices in their breathing zone simultaneuosly in the workplaces, and the sampling analytical results were compared with those of charcoal tube. The results obtained are as follows: 1. The concentrations of toluene and xylene measured by passive sampler were slightly higher than those of charcoal tube, but there were no significant statistical differences between two methods. 2. The concentrations of MEK and cyclo-hexanone measured by passive sampler in low exposure workplace (below 0.20 of MEK TLV levels and 0.1 of cyclo-hexanone TLV levels) were about 2 times higher than that of charcoal tube sampling. While, absorption efficiency of passive sampler was reduced according to increasing concentration measurements of MEK and cyclo-hexanone in air. 3. The ratios of concentrations of toluene, xylene, MEK and cyc1o-hexanone measured by passive sampler over those measured by charcoal tube were 1.11, 1.07, 1.63 and 3.65 respectively. 4. The percentages of concentration of passive samplers within 0.75 and 1.25 of charcoal tube value as a reference value of 1.0 were 57% in toluene, 74% in xylene, 34% in MEK and 32% in cyclo-hexanone respectively. 5. The correlation coefficients of toluene, xylene, MEK and cyclo-hexanone between passive sampler and charcoal tube sampler were 0.963, 0.957, 0.943 and 0.562 with statistical significance.

• Journal of Embryo Transfer
• /
• v.21 no.3
• /
• pp.169-175
• /
• 2006

The objective of this study was carried out to examine the polar body extrusion of in vitro matured porcine follicular oocytes as a non-invasive marker of oocyte quality to know the developmental competence in advance. The porcine oocytes matured for 48 hours were examined the polar body extrusion and some parts were stained. The examined oocytes were matured for additional $16{\sim}18$ hours and activated with 7% ethanol and cultured in $5{\mu}g/ml$ cytochalasin B for 5 hours for diploid formation. The treated oocytes were washed and cultured for 7 days. The polar body extrusion and degeneration rates were varied with $9.9{\sim}52.4%$ and $21.4{\sim}61.8%$ by repetition. The polar body extruded oocytes were shown the polar body chromosome and metaphase II plate by staining. However the non-extruded oocytes were shown expanded nucleus with 39.1%, premature chromosome condensation with 19.6%, metaphase I plate with 10.9 %, metaphase II with 13%, condensed chromatin with 6.5%, and absent nuclear material with 8.7%. The oocytes that were not examined for the polar body extrusion were cleaved 45.0%, and developed to blastocyst stage with 11.3%. In examined oocytes for polar body extrusion,. the polar body extruded oocytes were cleaved 94.2% and developed with 42.5%. This result suggests that discarding of the degenerating oocytes and oocytes that not extruded polar body will be effective for experiments of culturing effect in porcine embryos and embryo biotechnology.

• The Korean Journal of Nuclear Medicine
• /
• v.33 no.2
• /
• pp.131-142
• /
• 1999

Purpose: Either gated myocardial perfusion SPECT or attenuation corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease. We investigated in this study whether gating or attenuation correction improved diagnostic performance of rest/stress perfusion SPECT in patients having intermediate pre-test likelihood of coronary artery disease. Materials and Methods: Sixty-eight patients underwent rest attenuation-corrected T1-20l/dipyridamole stress gated attenuation-corrected Tc-99m -MIBI SPECT using an ADAC vertex camera (M:F=29:39, aged $59{\pm}12$ years, coronary artery stenosis ${\geq}70%$, one vessel: 13, two vessel: 18, three vessel: 8, normal: 29). Using a five-point scale, three physicians graded the post-test likelihood of coronary artery disease for each arterial territory (1:normal, 2: possibly normal, 3:equivocal, 4. possibly abnormal, 5: abnormal). Sensitivity, specificity and area under receiver-operating-characteristic curves were compared for each operator between three methods : (A) non-attenuation-corrected SPECT; (B) gated SPECT added to (A): and (C) attenuation-corrected SPECT added to (B). Results: When grade 3 was used as the criteria for coronary artery disease, no differences in sensitivity and specificity were found between the three methods for each operator. Areas under receiver-operating-characteristic curves for diagnosis of coronary artery disease revealed no differences between each modality (p>0.05). Conclusion: In patients at intermediate risk of coronary artery disease, gated SPECT and attenuation- corrected SPECT did not improve diagnostic performance.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.6
• /
• pp.789-792
• /
• 2010

Major impacts of climate change expert that soil erosion rate may increase during the $21^{st}$ century. This study was conducted to assess the potential impacts of climate change on soil erosion by water in Korea. The soil loss was estimated for regions with the potential risk of soil erosion on a national scale. For computation, Universal Soil Loss Equation (USLE) with rainfall and runoff erosivity factors (R), cover management factors (C), support practice factors (P) and revised USLE with soil erodibility factors (K) and topographic factors (LS) were used. RUSLE, the revised version of USLE, was modified for Korean conditions and re-evaluate to estimate the national-scale of soil loss based on the digital soil maps for Korea. The change of precipitation for 2010 to 2090s were predicted under A1B scenarios made by National Institute of Meteorological Research in Korea. Future soil loss was predicted based on a change of R factor. As results, the predicted precipitations were increased by 6.7% for 2010 to 2030s, 9.5% for 2040 to 2060s and 190% for 2070 to 2090s, respectively. The total soil loss from uplands in 2005 was estimated approximately $28{\times}10^6$ ton. Total soil losses were estimated as $31{\times}10^6$ ton in 2010 to 2030s, $31{\times}10^6$ ton in 2040 to 2060s and $33{\times}10^6$ ton in 2070 to 2090s, respectively. As precipitation increased by 17% in the end of $21^{st}$ century, the total soil loss was increased by 12.9%. Overall, these results emphasize the significance of precipitation. However, it should be noted that when precipitation becomes insignificant, the results may turn out to be complex due to the large interaction among plant biomass, runoff and erosion. This may cause increase or decrease the overall erosion.

• Korean Chemical Engineering Research
• /
• v.60 no.4
• /
• pp.535-543
• /
• 2022

A CPFD (Computational particle fluid dynamics) model of solar fluidized bed receiver of silicon carbide (SiC: average d_p=123 ㎛) particles was established, and the model was verified by comparing the simulation and experimental results to analyze the effect of particle behavior on the performance of the receiver. The relationship between the heat-absorbing performance and the particles behavior in the receiver was analyzed by simulating their behavior near bed surface, which is difficult to access experimentally. The CPFD simulation results showed good agreement with the experimental values on the solids holdup and its standard deviation under experimental condition in bed and freeboard regions. The local solid holdups near the bed surface, where particles primarily absorb solar heat energy and transfer it to the inside of the bed, showed a non-uniform distribution with a relatively low value at the center related with the bubble behavior in the bed. The local solid holdup increased the axial and radial non-uniformity in the freeboard region with the gas velocity, which explains well that the increase in the RSD (Relative standard deviation) of pressure drop across the freeboard region is responsible for the loss of solar energy reflected by the entrained particles in the particle receiver. The simulation results of local gas and particle velocities with gas velocity confirmed that the local particle behavior in the fluidized bed are closely related to the bubble behavior characterized by the properties of the Geldart B particles. The temperature difference of the fluidizing gas passing through the receiver per irradiance (∆T/I_DNI) was highly correlated with the RSD of the pressure drop across the bed surface and the freeboard regions. The CPFD simulation results can be used to improve the performance of the particle receiver through local particle behavior analysis.