• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.469-482
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• 2018

This research has developed the criteria and index for systematically and objectively assessing the quality of river water by fixing the various factors that affect Gyeongin ARA waterway's water quality through analysis with the Delphi Technique and analytic hierarchy program (AHP) Method. Based on the results, the highest criteria are, in order of importance, physical and environmental factors 28%, administrative factors 26%, natural fixed factors 26% and finally, cultural and social factors 20%. The three dimensions of the criteria show that for the internal physical and environmental factors, the most important are the loss of self-purification capacity, and the external factors are Gulpocheon and the sludge deposit due to Gyulhweon-weir the bridge. The facility factor in management was affected by the coagulation and waste water disposal facilities. The problem for the policy and institutional factors was seen in the regulatory area. The aquatic ecology/ point pollution source for the natural fixed factors show that it is due to the polluted water of Gulpo-cheon and the living environment/ non-point pollution source is shown through the inflow water from other rivers. Cultural and social factors show that the economical causes were due to the cargo and passenger flight operations and the external factors of having a lack of sewage treatment equipment have an importance effect. In order to estimate the order of priority through logical evidence and objectivity, future research must be continued on the evaluation indexes to measure the specific methodology and technique needed to improve the Gyeongin ARA Waterway.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.44-54
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• 2018

In the construction project, the design field has a crucial effect on the success or failure of the final product, and it is becoming more important as a core area of national industrial development because it creates high value added by technology. In addition, since the design work is carried out based on professional technical personnel, in order to secure the quality and competitiveness of the design, it is necessary to continuously input the excellent manpower and develop the technology, and above all, the appropriate design cost must be ensured. However, as a result of reviewing the current status of the design cost criterion in Korea, problems such as mixed cost calculation method, inaccuracy of construction cost ratio method, and inactivation of cost plus fixed fee method were analyzed. Therefore, it is difficult to calculate the fair value reflecting the characteristics of the project when calculating the construction design price. Therefore, the price criterion should be improved so that the fair value of the design can be determined according to the contents of the project, By analyzing the correlation and multiple regression analysis of the projects and price information of the completed road construction design, the factors influencing the design price and the level of influence were analyzed.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.5
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• pp.642-653
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• 2006

Purpose : The purpose of this study was to investigate the effect of the output energy(voltage) of laser welding on the strength and properties of joint of cast titanium(CP Gr II) and titanium alloy(Ti-6Al-4V). Material and method : Cast titanium and its alloy rods(ISO6871) were prepared and perpendicularly cut at the center of the rod. After the cut halves were fixed in a jig, and the joints welded with a laser-welding machine at several levels of output voltage of $200V{\sim}280V$. Uncut specimens served as the non-welded control specimens The pulse duration and pulse spot size employed in this study were 10ms and 1.0mm respectively. Tensile testing was conducted at a crosshead speed of 0.5mm/min. The ultimate tensile strength(MPa) was recorded, and the data (n=6) were statistically analyzed by one-way analysis of variance(ANOVA) and Scheffe's test at ${\alpha}$=0.05. The fracture surface of specimens investigated by scanning electron microscope (SEM). Vickers microhardness was measured under 500g load of 15seconds with the optimal condition of output voltage 280V. Results : The results of this study were obtained as follows, 1. When the pulse duration and spot size were fixed at 10ms and 1.0mm respectively, increasing the output energy(voltage) increased UTS values and penetration depth of laser welded to titanium and titanium alloy. 2. For the commercial titanium grade II, ultimate tensile strength(665.3MPa) of the specimens laser-welded at voltage of 280V were not statistically(p>0.05) different from the non-welded control specimens (680.2MPa). 3. For the titanium alloy(Ti-6Al-4V), ultimate tensile strength(988.3MPa) of the specimens laser-welded at voltage of 280V were statistically(p<0.05) different from the non-welded control specimens (665.0MPa). 4. The commercial titanium grade II and titanium alloy(Ti-6Al-4V) were Vickers microhardness values were increased in the fusion zone and there were no significant differences in base metal, heat-affected zone.

• MALSORI
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• no.21_24
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• pp.43-89
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• 1992

In this thesis, the prominent aspect of word accent in standard Korean is studied by auditory test and acoustic analysis experiment. The definition of 'accent' is, following Hoyoung Lee's discussion(1990), to be described as 'the means whereby a focused part of an utterance is made to stand out in order to concentrate the hearer's attention on it.' That is to say, the ten of 'accent' may be described in terms of phonological phenomenon and the accented syllable can be phonetically prominent as the result of those phonological process. Prosodic features may have different characteristics in different languages whether they contain linguistically important functions or not. Thus the characteristics of word accent in standard Korean will be determined as the content and trait of prosodic features. Following this viewpoint, present study looked over prosodic features which may effect the characteristics of word accent in standard Korean, through systematic experimental procedure. And the result of this experiment has been verified by statistical method, the T-test, for the purpose of identifying the relatedness among prosodic features(parameters). This thesis, therefore, aimed to investigate the intrinsic acoustic and physical qualities of the word accent in standard Korean. Nonsense words composed by 'mal' and 'ma' which can be divided into 'heavy syllable' and 'light syllable' quoted from Hyman(1975) have been classified into 28 types with respect to syllable numbers(2 syl., 3 sy1., 4 syl.) and these words have become the target of auditory test and acoustic experiment. As the result of those experimental Procedures, the word accent in standard Korean may be said that it has a tendency of fixing first two syllables regardless of syllable numbers. The syllable types of HH, HL, LL in the first two syllables may be prominent at first syllable and the type of H may be at second syllable. Various prosodic features(parameters) including duration, intensity, and Fo(purely phonetic terms) were also strengthened in those positions. The result of this experiment can be cleared up like these : 1. The most important feature is proved as 'duration', the feature of intensity resulted in more subsidiary one than the feature of duration. 2. Fo( fundamental frequency) could be observed as having some coherent contour through almost all syllable types(99 ％), that is, in 2 syllable types, it had rising contour, in 2 syllable types, rising-falling contour, and in 4 syllable types, it contained rising-falling-rising contour. The result of auditory test was different with those contour forms of all Fo surveyed. With respect to these results, the discuss for Fo is determined' to be excluded comparing other features. 3. Finally, this thesis resulted in a decision that the word accent in standard Korean may has fixed(somewhat weaker) accent, especially fixed at first two syllables in almost all words. 4. Various kinds of syllable types related with 2,3,4 syllables, therefore, can be reclassified into 4 types of HH, HL, LH, LL following the concept of accent fixing placement(i.e. first two syllables). In these 4 types, the types of HH, HL, LL were prominent at the position of the first syllable , and the type of LH was prominent at the second syllable otherwise.

• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.935-946
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• 2016

In this paper, we analyzed wage determinants of the vocational high school graduates utilizing both individual-level and work region-level variables. We formulate the models in the way wage determination has multi-level structure in the sense that individual wage is influenced by individual-level variables (level-1) and work region-level (level-2) variables. To incorporate dependency between individual wages into the model, we utilize hierarchical linear model (HLM). The major results are as follows. First, it is shown that the HLM model is better than the OLS regression models which do not take level-1 and level-2 variables simultaneously into account. Second, random effects on sex, maester dummy and engineering dummy variables are statistically significant. Third, the fixed effects on business hours and mean wage of regular job for level-2 variables are statistically significant effect individual-level wages. Finally, parental education level, parental income, number of licenses and high school grade are statistically significant for higher individual-level wages.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.223-237
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• 2006

The purpose of the present study was to evaluate the effect of bone graft materials including deproteinized bovine bone(DBB), demineralized freeze-dried bone(DFDB), freeze-dried bone(FDB) on bone formation in guided bone regeneration using perforated titanium membrane(TM). 16 adult male rabbits(mean BW 2kg) were used in this study and 4 rabbits allotted to each test group. Intramarrow penetration(diameter 6.5mm) was done with round carbide bur on calvaria to promote blood supply and clot formation in the wound area. The test groups were devided into 4 groups as follows: TM only(test 1), TM +DBB(test 2), TM +DFDB(test 3), TM +FDB(test 4). Perforated titanium membrane was contoured in rectangular parallelepiped shape(0.5mm pore diameter, 10mm in one side, 2mm in inner height), filled the each graft material and placed on the decorticated carvaria. Perforated titanium membrane was fixed with resorbable suture materials. The animals were sacrificed at 2, 8 weeks after the surgery. Non-decalcified preparations were routinely processed for histologic analysis. The results of this study were as follows: 1. Perforated titanium membrane was biocompatible. 2. Perforated titanium membrane had capability of maintaining the space during the healing period but invasion of soft tissue through the perforations of titanium membrane decreased the space available for bone formation. 3. In test 1 group without bone graft material, the amount of bone formation and bone maturation was better than other test groups. 4. Among the graft materials, the effect of freeze-dried bone on bone formation was best. 5. In the test groups using deproteinized bovine bone, demineralized freeze-dried bone, bone formation was a little. The spacemaking capability of the membrane may be crucial for bone formation. The combined treatment with the perforated titanium membrane and deproteinized bovine bone or demineralized freeze-dried bone failed to demonstrate any added effect in the bone formation. Minimization of size and numbers of perforations of titanium membrane or use of occlusive titanium membrane might be effective to acquire predictable results in the vertical bone formation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.11-26
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• 2023

This study aimed to empirically analyze the effect of Korean companies' FDI(Foreign Direct Investment) on their financial performances, particularly divided into profitability, stability, growth and activity, while comparing distinct financial performances between SMEs(small and medium-sized enterprises) and large enterprises whose corporate attributes are different from each other. As research subjects, this study selected FDI Korean companies from the directory of oversea-expanded companies of KOTRA(Korea Trade-Investment Promotion Agency) and used financial data from a total of 409 companies(136 SMEs and 273 large enterprises) with complete financial data for the first five years after the initial investment out of all the financial data from 1990 to 2021. The analysis results can be summarized as follows; In the profitability sector, FDI had positive effects on ROA(Return on Assets) and ROS(Return on Sales) of SMEs, while having negative effects on those of large enterprises to the contrary. In the stability sector, FDI had no statistical significance for SMEs, while having significantly negative effect on LEV(Debt to Equity Ratio) of large enterprises. In the growth sector, FDI had significantly negative effect on AGR(Asset Growth) of SMEs, but showed no significant results for large enterprises. In the activity sector, FDI showed no statistical significance for SMEs, while having positive effects on ATR(Asset Turnover Ratio) and FATA(Fixed Asset Turnover Ratio) of large enterprises. In conclusion, it was found that when having made FDI, SMEs and large enterprises showed different financial performances from each other in terms of profitability, stability, growth and activity.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5777-5783
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• 2012

Published data on the associations between tumor necrosis factor-alpha (TNF-${\alpha}$) promoter -308G>A and -238G>A polymorphisms and cervical cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Data were collected from MEDLINE and PubMed databases. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in a fixed/random effect model. 13 separate studies including 3294 cases and 3468 controls were involved in the meta-analysis. We found no association between TNF-${\alpha}$-308G>A polymorphism and cervical cancer in overall population. In subgroup analysis, significantly elevated risks were found in Caucasian population (A vs. G: OR = 1.43, 95% CI = 1.00-2.03; AA vs. GG: OR = 2.09, 95% CI = 1.34-3.25; Recessive model: OR = 2.09, 95% CI = 1.35-3.25) and African population (GA vs. GG: OR = 1.53, 95% CI = 1.02-2.30). An association of TNF-${\alpha}$-238G>A polymorphism with cervical cancer was found (A vs. G: OR = 0.61, 95% CI = 0.47-0.78; GA vs. GG: OR = 0.59, 95% CI = 0.45-0.77; Dominant model: OR = 0.59, 95% CI = 0.46-0.77). When stratified by ethnicity, similar association was observed in Caucasian population (A vs. G: OR = 0.62, 95% CI = 0.46-0.84; GA vs. GG: OR = 0.59, 95% CI = 0.43-0.82; Dominant model: OR = 0.60, 95% CI = 0.44-0.83). In summary, this meta-analysis suggests that TNF-${\alpha}$-238A allele significantly decreased the cervical cancer risk, and the TNF-${\alpha}$-308G>A polymorphism is associated with the susceptibility to cervical cancer in Caucasian and African population.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.4 s.74
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• pp.389-398
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• 2006

Structural optimization design has been developed with finite element analysis using effective and fast computational technology. Especially topology optimization design has been recently often used since it yields an optimal topology as well as an optimal shape under satisfied constraints. In general in finite element analysis, it is assumed that the structural material properties such as Young's modulus and Poisson's ratio and the variable of applied loading are fixed with obvious values in structure. However practically these values may take uncertainties because of environmental effect or manufactural error of structures. Therefore static or dynamic analysis of the structures may make an error, then finally it may have an influence on qualify of optimal design. In this study, the topology optimization design of structure is carried out using so called the interval finite element method, and the analysis method Is proposed. The results are also validated by comparing with conventional topology optimization results of density distribution method and finite element analysis results. The present method can be used to predict the optimal topology of linear elastostatic structures with respect to structural uncertainty of behavior.

• Journal of Distribution Research
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• v.16 no.5
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• pp.171-192
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• 2011

This paper focuses on the retail industry of industrial share of the GDP, productivity of distribution industry and input-out analysis between Korea and Japan, also results are summarized as follows. First, the share of GDP in agriculture, forestry and fisheries of the both countries is falling. That of manufacture increases in South Korea, while Japan is falling. While distribution industry shows vice versa. Employed population by industry is falling both countries also. The relative labor productivity shows that agriculture, forestry and fisheries, retail industry needs more labor, while manufacture has been met for both countries. Second, compare to Japan, the retail industry of Korea has been increased since 1990. Likewise, overall productivity of distribution industry in Korea has been increased while almost that of Japan has declined. Third, production inducement effects of Japan are greater than that of Korea. On the other hand, import inducement effects show vice versa. Fourth, as shown from the final demand of distribution industry and the rate of dependence on production inducement, we can see that the “increase in stocks” increases while gross government fixed capital formation shows vice versa. Korea's private consumption expenditure increases while Japan shows versa. South Korea's government consumption expenditure and exports are rising, on the other hand, that of Japan is declining. Fifth, the rate of dependence on distribution industry and import inducement shows the same tendency from both countries. As we can see from the private consumption expenditure, government consumption expenditure, gross government fixed capital formation, gross private fixed capital formation, increase in stocks, the rate of dependence on import inducement is more effective than the rate of dependence on production inducement. While the exports are comparatively ineffective. Sixth, the degrees of influence of retail industry are similar between Korea and Japan, while sensitivity of the Korean industry has been weakened. In this sense, strong policies are needed to boost the industry. Seventh, the investments in the retail industry of Korea showed the public-led trend, while Japan showed private sector-led investment trend. The investment trend of Korea's retail industry will be switched into private sector-led investment step by step in the future. This finding will be an important clue to set the policy direction of Korea distribution industry. Finally, both Korea and Japan are still in need of employment in retail industry. Not addressed in this paper, such as value-added-induced effects, employment inducement effect, will be remaining challenges in the following paper.