• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.218-223
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• 1993

In this paper, we present a full digital control scheme which controls currents and speed of the permanent magnet AC servo motor with large range of bandwidth and high performance. The current equations of the permanent magnet AC servo motor are linearized by feedback linearization technique. Both acceleration feedforward terms and IP controllers, whose gains are functions of motor speed, are used in order to control motor currents. In addition the phase delays in current control loops are compensated by placing phase lead-lag compensators after current commands, which make it possible to avoid high gains in the current controllers. Unity power factor can be achieved by the proposed current controller. Pulsewidth modulation is performed by way of the well-known comparison with a triangular carrier signals. The velocity controller is designed on the basis of the linearized model of the permanent magnet AC servo motor by the proposed current controller. The performance of the entire control system is analyzed in the presence of uncertainty in the motor parameters. The proposed control scheme is implemented using the digital signal processor-based controller composed of an Analog Device ADSP 2111 and a NEC78310. The pulsewidth modulation (PWM) signals are generated through a custom IC, SAMSUNG-PWM1, which has the outputs of current controllers as input. The experimental results show that the permanent magnet AC servo motor can be always driven with high dynamic performance by the proposed full digital control scheme of motor speed and motor current.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.24-25
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• 2003

The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. I will talk about positional cloning of two developmental mutants in zebrafish. The first mutant is headless: The vertebrate organizer can induce a complete body axis when transplanted to the ventral side of a host embryo by virtue of its distinct head and trunk inducing properties. Wingless/Wntantagonists secreted by the organizer have been identified as head inducers. Their ectopic expression can promote head formation, whereas ectopic activation of Wnt signalling during early gastrulation blocks head formation. These observations suggest that the ability of head inducers to inhibit Wntsignalling during formation of anterior structures is what distinguishes them from trunk inducers that permit the operation of posteriorizing Wnt signals. I describe the zebrafish headless (hdl) mutant and show that its severe head defects are due to a mutation in T-cell factor-3 (Tcf3), a member of the Tcf/Lef family. Loss of Tcf3 function in the hdl mutant reveals that hdl represses Wnt target genes. I provide genetic evidence that a component of the Wntsignalling pathway is essential in vertebrate head formation and patterning. Second mutant is mind bomb: Lateral inhibition, mediated by Notch signaling, leads to the selection of cells that are permitted to become neurons within domains defined by proneuralgene expression. Reduced lateral inhibition in zebrafish mib mutant embryos permits too many neural progenitors to differentiate as neurons. Positional cloning of mib revealed that it is a gene in the Notch pathway that encodes a RING ubiquitin ligase. Mib interacts with the intracellular domain of Delta to promote its ubiquitylation and internalization. Cell transplantation studies suggest that mib function is essential in the signaling cell for efficient activation of Notch in neighboring cells. (중략)

• Journal of Life Science
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• v.18 no.2
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• pp.162-166
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• 2008

The production of heteropolysaccharide-7 (PS-7) by Beijerinckia indica (B. indica L3) was evaluated in shaker flask culture. The medium optimization was studied using response surface methodology (RSM). A five-level three-factor central composite design was employed to determine the maximum PS-7 yield at optimum levels for whey lactose, glucose and ammonium nitrate contents. The validity of the model could be determined by the regression coefficient, $R^2$. The values of $R^2$ were 0.72, 0.64 and 0.85 in PS-7, DCW and viscosity, respectively. The optimal medium combinations of whey lactose, glucose and ammonium nitrate concentrations on the PS-7 production were whey lactose (2%), glucose (1 %) and ammonium nitrate 5 mM, respectively. The result indicated that PS-7 production was affected significantly by the addition of glucose to whey lactose based on medium and C/N ratio.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.3
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• pp.328-342
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• 1999

This study was performed to investigate the factors related to tooth wear. For this study, 78 patients with temporomandibular disorders and 76 dental students without any signs and symptoms of temporomandibular disorders were selected as the patients group and as the normal group, respectively. Preferred chewing side, Angle's classification, lateral guidance pattern, head and shoulder posture were observed clinically. Electromyographic activity of anterior temporalis and masseter muscle were recorded with $BioEMG^{(R)}$ and occlusal status were recorded with $T-Scan^{(R)}$. Wear facet area of each tooth was measured from working model of upper arch corresponding to the occlusal status from T-Scan. Wear facet area were measured with planimeter in $mm^2$. Total area were divided into incisal, canine, posterior tooth area. Anterior wearfacet area was incisor area plus canine area, and unilateral area was anterior area plus posterior area. The data collected were analyzed by SAS statistical program and the results of this study were as follows: 1. There was no significant difference between the two groups in total werafacet area, and male subjects showed tendency to have larger area in the normal group but female subjects showed tendency vice versa. 2. There was no significant difference related to preferred chewing side and Angle's classification, however some difference was observed by lateral guidance pattern. Anterior wear facet area in subjects of canine guidance was the largest in the three subgroups. 3. Subjects with head tilting to right side had larger posterior and total area, and subjects with higher shoulder in right side had larger canine and anterior area than any other subgrous. 4. Electromyographic activity of masseter muscle was more correlated with wear facet area than anterior temporalis muscle, and tooth contact number and force were significantly correlated with wear facet area, but the most important factor affecting tooth attrition was age.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.110-116
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• 2005

Background: As an attempt to develop a strategy to improve the protective immune response to GM-CSF-secreting CT26 (GM-CSF/CT26) tumor vaccine, we have investigated whether the apoptogenic treatment of GM-CSF/CT26 prior to vaccination enhances the induction of anti-tumor immune response in mouse model. Methods: A carcinogeninduced mouse colorectal tumor, CT26 was transfected with GM-CSF gene using a retroviral vector to generate GM-CSF-secreting CT26 (CT26/GM-CSF). The CT26/GM-CSF was treated with ${\gamma}$-irradiation or mitomycin C to induce apoptosis and vaccinated into BALB/c mice. After 7 days, the mice were injected with a lethal dose of challenge live CT26 cells to examine the protective effect of tumor vaccination in vivo. Results: Although both apoptotic and necrotic CT26/GM-CSF vaccines were able to enhance anti-tumor immune response, apoptotic CT26/GM-CSF induced by pretreatment with ${\gamma}$-irradiation (50,000 rads) was the most potent in generating the anti-tumor immunity, and thus 100% of mice vaccinated with the apoptotic cells remained tumor free for more than 60 days after tumor challenge. Conclusion: Apoptogenic pretreatment of GM-CSF-secreting CT26 tumor vaccine by ${\gamma}$-irradiation (50,000 rads) resulted in a significant enhancement in inducing the protective anti-tumor immunity. A rapid induction of apoptosis of CT26/GM-CSF tumor vaccine at the vaccine site might be critical for the enhancement in anti-tumor immune response to tumor vaccine.

• IMMUNE NETWORK
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• v.13 no.5
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• pp.213-217
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• 2013

Enterotoxigenic Bacteroides fragilis (ETBF) is a human gut commensal bacteria that causes inflammatory diarrhea and colitis. ETBF also promotes colorectal tumorigenesis in the Min mouse model. The key virulence factor is a secreted metalloprotease called B. fragilis toxin (BFT). BFT induces E-cadherin cleavage, cell rounding, activation of the ${\beta}$-catenin pathway and secretion of IL-8 in colonic epithelial cells. However, the precise mechanism by which these processes occur and how these processes are interrelated is still unclear. E-cadherin form homophilic interactions which tethers adjacent cells. Loss of E-cadherin results in detachment of adjacent cells. Prior studies have suggested that BFT induces IL-8 expression by inducing E-cadherin cleavage; cells that do not express E-cadherin do not secrete IL-8 in response to BFT. In the current study, we found that HT29/C1cells treated with dilute trypsin solution induced E-cadherin degradation and IL-8 secretion, consistent with the hypothesis that E-cadherin cleavage causes IL-8 secretion. However, physical damage to the cell monolayer did not induce IL-8 secretion. We also show that EDTA-mediated disruption of E-cadherin interactions without E-cadherin degradation was sufficient to induce IL-8 secretion. Finally, we determined that HT29/C1 cells treated with LiCl (${\beta}$-catenin activator) induced IL-8 secretion in a dose-dependent and time-dependent manner. Taken together, our results suggest that BFT induced IL-8 secretion may occur by the following process: E-cadherin cleavage, disruption of cellular interactions, activation of the ${\beta}$-catenin pathway and IL-8 expression. However, we further propose that E-cadherin cleavage per se may not be required for BFT induced IL-8 secretion.

• International Commerce and Information Review
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• v.17 no.3
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• pp.279-298
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• 2015

This study is intended to grope for a way of strengthening the independent competitiveness of Korean design industry by deducing objective value evaluation factors in design and by closely examining what relation these factors have with the competitiveness of design-specialized company in global markets in order to reinforce the qualitative value system of design, and in order to strengthen the industrial competitiveness of design. First of all, this study defined the objective evaluation factors in design as the quantification of measurement evaluation, the consistency of process, the compatibility of project, and logical persuasiveness, and defined the competitiveness factor in design-specialized company as the reliability and service quality of company, and established a research model. According to the results of test, most of hypotheses were accepted. However, it was understood that the quantification of evaluation didn't have direction effect on the service quality of design-specialized company.

• International Commerce and Information Review
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• v.14 no.3
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• pp.185-207
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• 2012

Vietnam is the easternmost country on the Indochina Peninsula in Southeast Asia. Many Korean companies have recently invested their factories to Vietnam from China. This Study measures the entry determinants and outcomes of Vietnam foreign direct investment of the Korea company. This study developed a research model to determinant factor in the Vietnam market entry and collected 98 survey responses from the Korean company to Vietnam investment. In the article analysis, Multiple regression results show that Vietnam investment outcome review are positively affected by "Scale of Investment company", "International Experience of Investment company", "Marketing Skill of Investment company" and "Vietnam's Market Scale", "Vietnam's Market Environment" factors in all a hypothesis. However, the result of this analysis showed that the "Financial management of investment company", and "Organization management of investment company" as independence is not statistically significant. This article suggests that the investment outcome of Vietnam foreign direct investment should take earned of the Korea company in Vietnam market.

• The Journal of Information Systems
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• v.17 no.2
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• pp.1-26
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• 2008

SCM is one of the important key issues in Internet-based business environment. This study intends to suggest a research model to measure the influence of environmental, organizational, information technology factors on organizational performance using the four perspectives of balanced scorecard (BSC). 9 independent variables and 4 dependent variables were adopted from existing literature review. 103 companies data were collected by survey. Four hypotheses in this study were generated to analyze the positive relationship of environmental, organizational, information systems on organizational performance with 4 perspectives of BSC. The results of hypothesis testing show as follows. First, organizational performance of learning and growth perspective has a positive influence of IS maturity, process innovation, top management support, use of SCM package, IS interoperability, and objectives sharing. Second organizational performance of infernal process perspective has a positive influence of process innovation, IS interoperability, objectives sharing, top management support, use of SCM package, competitiveness, and IS maturity. Third, organizational performance of customer perspective has a positive influence of IS interoperability, objectives sharing, process innovation, IS maturity, competitiveness, and use of SCM package. Finally, organizational performance of financial perspective has a positive influence of process in innovation, use of SCM package, IS maturity, objectives sharing, IS interoperability, and top management support. The contribution of this study is that it provides a conceptual framework and empirical evidences of the causal relationship between environmental, organizational, IS factor and organizational performance with 4 perspectives of BSC.

• Journal of Global Scholars of Marketing Science
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• v.17 no.3
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• pp.133-151
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• 2007

The purpose of this article is to examine the effects of item parceling on the consistency of significance testing of the causal parameters with regard to the relationship between the relevant constructs, as well as the effects of the item parceling on the goodness-of-fit indices of LISREL's general models. Most of the researchers' major purpose of using structural equation modeling (SEM) is to test their research hypotheses associated with the causal parameters. Therefore, we investigated three general models of LISREL, rather than the frequently used confirmatory factor analytic (CFA) models by many other researchers. The results of the study showed that there was a high level of consistency in the calculated test statics of causal parameters between the item-parceled solutions and the item-level solutions, and that the item-parceled solutions had better goodness-of-fit indices, such as GFI, AGFI, CFI, and NFI, than the solutions at the item level. However, in terms of RMSEA, there was no such tendency.