• 한국데이터정보과학회:학술대회논문집
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• 2002.06a
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• pp.155-167
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• 2002

In this paper we consider optimal designs of partially constant-stress life testing which is deviced for three-component mixed systems with the considerably long time. Mixed systems are jointed serial system with parallel system. Test items are run at both use condition and accelerated condition until a specified censoring time. The optimal criterion for the sample-proportion allocated to accelerated condition is to minimized asymptotic variance of the maximum likelihood estimators of the acceleration factor and hazard rates.

• Journal of the Korean Electrochemical Society
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• v.7 no.1
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• pp.44-48
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• 2004

The two-component type enzyme amplified amperometric DNA assay is described to use an ambient $O_2$ of the substrate of the DNA labeling enzyme. Although the assay detects DNA only at > 0.5M concentration, a concentration $\~10^6$ fold higher than the sandwich-type enzyme amplified amperometric DNA assay, it can be run with an always available substrate. The assay utilizes screen-printed carbon electrodes (SPEs) which were pre-coated by a co-electrodeposited film of an electron conducting redox hydrogel and a 37-base long single-stranded DNA sequence. The DNA in the electron conducting film hybridizes and captures, when present, the 37-base long detection-DNA, which is labeled with bilirubin oxidase (BOD), an enzyme catalyzing the four-electron reduction of $O_2$ to water. Because the redox hydrogel electrically connects the BOD reaction centers to the electrode, completion of the sandwich converts the film from non-electrocatalytic to electrocatalytic for the reduction of $O_2$ to water when the electrode is poised at 200 mV vs. Ag/hgCl. The advantage or the assay over the earlier reported sandwich type enzyme amplified amperometric DNA assay, in which the amplifying enzyme was horseradish peroxidase, is that it utilizes ambient $O_2$ instead of the less stable and naturally unavailable $H_2O_2$.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.3
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• pp.81-89
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• 2019

Many authors have examined the impact of public spending on economic growth. This study uses ordinary least-squares technique to test the effect of state budget expenditure with two major components: development investment expenditure and recurrent expenditure on Vietnamese economy for the period 2000-2017. The empirical results show that the state budget expenditure of Vietnam has positive effect on the economy, however each main component has different impacts. Recurrent expenditure has significant positive impact on Vietnamese economy while there has no evidence to affirm the relationship between the development investment expenditure and the economic growth. Vietnamese government should restructure the state budget to enhance the positive effect on the economy. In the short run, Vietnam should not increase development investment expenditure due to low efficency in public investment. In the long run, it is necessary to economize recurrent expenditure to reserve a reasonable proportion of state budget for development investment expenditure to build infrastructure for developing the economy. The state budget expenditure should be restructured towards prioritizing recurrent expenditure on human and social relief, reducing public administration expenditure, allocating investment capital from the state budget for key and pervasive projects, avoiding spreading out investments as well as crowding out private investments.

• East Asian Economic Review
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• v.21 no.3
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• pp.201-230
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• 2017

This paper studies the long-run behavior of relative price dispersion among cities in Korea with a special emphasis on heterogeneous transitional patterns of price level dynamics. Formal statistical tests indicate considerable evidence for rejecting the null of relative price level convergence among the majority of cities over the sample period of 1985-2015. The analysis of gravity model suggests that the effect of transportation costs on intercity price level differentials is limited, while other socioeconomic factors, such as income, input factor prices, demographic structure, and housing price growth, play key roles in accounting for persistent regional price level disparities. Individual price levels are found to be better explained by a multiple-component model, and the deviations from PPP may be attributed to distinct stochastic common trends that are characterized by income and demographic structure.

• Journal of applied mathematics & informatics
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• v.8 no.1
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• pp.199-212
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• 2001

We consider a k-out-of-n system with repair under T-policy. Life time of each component is exponentially distributed with parameter $\lambda$. Server is called to the system after the elapse of T time units since his departure after completion of repair of all failed units in the previous cycle or until accumulation of n-k failed units, whichever occurs first. Service time is assumed to be exponential with rate ${\mu}$. T is also exponentially distributed with parameter ${\alpha}$. System state probabilities in finite time and long run are derived for (i) cold (ii) warm (iii) hot systems. Several characteristics of these systems are obtained. A control problem is also investigated and numerical illustrations are provided. It is proved that the expected profit to the system is concave in ${\alpha}$ and hence global maximum exists.

• Journal of Korean Society for Quality Management
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• v.33 no.3
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• pp.91-104
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• 2005

Tolerance analysis plays an important role in design and manufacturing stages for reducing manufacturing cost by improving producibility. In most production processes encountered in practice, a process mean may shift or drift in the long run although process is in control. This study discusses the feasibility of three most common inflation factors(Bender, Gilson and Six Sigma) as a correction to Root Sum of Squares(RSS) method to compensate heuristically for a shift of process mean and nonnormal component distributions from simulation experiments and proposes the guidelines for choosing the inflation factor.

• Wind and Structures
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• v.25 no.1
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• pp.63-77
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• 2017

When railway vehicles run by towers of long span bridges, the railway vehicles might experience a sudden load-off and load-on phenomenon in crosswind conditions. To ensure the running safety of the railway vehicles and the running comfort of the passengers, some studies were carried out to investigate the impacts of sudden changes of aerodynamic loads on moving railway vehicles. In the present study, the aerodynamic coefficients which were measured in wind tunnel tests using a moving train model are converted into the aerodynamic coefficients in the actual scale. The three-component aerodynamic loads are calculated based on the aerodynamic coefficients with consideration of the vehicle movement. A three-dimensional railway vehicle model is set up using the multibody dynamic theory, and the aerodynamic loads are treated as the inputs of excitation varied with time for kinetic simulations of the railway vehicle. Thus the dynamic responses of the railway vehicle passing by the bridge tower can be obtained from the kinetic simulations in the time domain. The effects of the mean wind speeds and the rail track positions on the running performance of the railway vehicle are discussed. The three-component aerodynamic loads on the railway vehicle are found to experience significant sudden changes when the vehicle passes by the bridge tower. Correspondingly, such sudden changes of aerodynamic loads have a large impact on the dynamic performance of the running railway vehicle. The dynamic responses of the railway vehicle have great fluctuations and significant sudden changes, which is adverse to the running safety and comfort of the railway vehicle passing by the bridge tower in crosswind conditions.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.3
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• pp.343-357
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• 1999

The color change of maxillofacial silicone has been attributed to certain environmental factors such as exposure to the UV component of natural sunlight, wetting and drying of the elastomer and surface abrasion resulting from the application and removal of cosmetics. The purpose of this study was to evaluate the color change of maxillofacial silicone (Silastic MDX4-4210) according to type of pigment (cadmium yellow, titanium white, cosmetic red), and UV absorber application method after 200, 400, and 600 hours of 350nm UV light irradiation. The results were as follows. 1. According to type of pigments, after 200 hours cosmetic red showed significantly larger color change than cadmium yellow and titanium white, and after 400 and 600 hours color change significantly decreased in the order of cosmetic red, cadmium yellow, and titanium white (p<0.05). 2. In the cadmium yellow group, after 200 hours, the non-treatment group showed significantly larger color change, but after 400 and 600 hours, color change significantly decreased in the order of non-treatment, surface application and mixed group (p<0.05). 3. In the titanium white group, there was no significant color change difference between the three groups after 200 and 400 hours, but after 600 hours, the mixed group showed significantly smalt or color change than the non-treatment and surface application groups (p<0.05). 4. In the cosmetic red group, there was significant decrease in color change in the order of non-treatment, surface application and mixed group (p<0.05). From the results above, the effect of UV light absorber differed according to the type of pigment, but mixing UV light absorber with maxillofacial silicone is thought to give superior resistance against UV light irradiation in the long run.

• Environmental and Resource Economics Review
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• v.20 no.3
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• pp.419-457
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• 2011

This study aims at understanding the characteristics of global economic models, which are widely used for climate change policy analysis. A literature review study was conducted in order to derive general features of top-down models such as CGE and bottom-up/hybrid models such as GTEM. Furthermore, a structural analysis was carried out by applying parameter and structural components from other models to a particular model to observe the potential differences in outcomes. Literature review shows that bottom-up or hybrid models generally have higher level of reduction potentials than top-down models in the long run. This contradicts the conclusion presented by IPCC, and raises the need for more rigorous investigation through structural analysis. Structural analysis of EPPA model indicates that the structural component of the energy sector in a particular model is the most influential factor in predicting baseline emissions and reduction potentials. This includes the structure among energy, capital, and labor inputs, and the substitution elasticities within the energy bundle. Technology bundle can establish the conclusions from literature review, and change in Armington elasticities do not significantly affect the outcome in aggregate.

• Archives of design research
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• v.11 no.1
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• pp.185-197
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• 1998

The domestic publishing market has heen ranked at No.7 in the word publishing market(stastics material in Cultu re and Gymnastics m inistrv )Es pe cia Ill'. publishing quantity of children'book is about to reacb No.3. Such a publishing condition i." showing that Korean publishing world has limit,llion of kind and genre despite of its quant.iative improvement On the ot.her hand. t',reign juvenile publi."hing has multi-publishing form, which is a simultaneous publishing with dolls, audio stuff, game programs and CD-ROM t.itles. Even the animation is considered as of the publication at the planning s tsge. However, when we take a look at domestic condition we come to know that Korean juvenile publishing has been occupied mostly by the studying book. Also, the cautious book selection by the well educated parents in l990's has brought up the change of juvenile publishing world. Such a presen t condition bears of juvenlie publi.,;hing world. Such a present condition bears problem, which is the checking 190 translat.ions among the published picture- books of the last ye ar children's book Nevertheless, there was a sucessful domestic planned creative picture book last year. That is "Puppy s shit", which was sold out 15 000 copies and be st se ller of children's book. Whe n we take a look at the commercial success of "Puppy s shit", it is possible that domestic work holds a position in the publishing market. "Puppy s shit" is the story about valuable nature with Korean styled illustration, which tells the prefemece of Korean book in do mestic pu blis hin f.i market. With the motto "Finding prospect of the Korean creative children's book", this paper was went throu gh. By searchinf.i for creative com ponent.s of picture-book planning such as theme, story, illustration, and edit design through the foreign picture-book "What 1 want. to know from the little mole is who made it on top of his head"-and domestic creative picture/book 'Puppy's shit", this study tried to tell a couple of things like followings publication of Korean creative picture book in t.he world. professional and more artistic inner fabric and originality(the relatio nship be tween stort and illu,tration), improvement of illustration through new formative language with well expressed con ten t, planning improvem ent of Korean creative pictive picture book including literary, artistic and educative component and finally examples of planning, artict and educative component and finally example, of planning the good book with a story and illu,;tration which can in the long run improve the value of life for the children.h can in the long run improve the value of life for the children.