• Communications for Statistical Applications and Methods
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• v.5 no.3
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• pp.607-621
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• 1998

When fitting a response surface model, the least squares estimates of the model's parameters and the prediction variance will generally depend on how the response surface design is blocked. That is, the choice of a blocking arrangement for a response surface design can have a considerable effect on estimating the mean response and on the size of the prediction variance even if the experimental runs are the same. Therefore, care should be exercised in the selection of blocks. In this paper, we prognose a graphical method for evaluating the effect of blocking in a response surface designs using cuboidal regions in the presence of a fixed block effect. This graphical method can be used to investigate how the blocking has influence on the prediction variance throughout the entire experimental region of interest when this region is cuboidal, and compare the block effect in the cases of the orthogonal and non-orthogonalblockdesigns, resfectively.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.369-376
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• 2005

This study aims to investigate and practically examine the effect of environmental qualifications based on the theoretical background on the area. On the basis of theoretical background, a study model was formulated in a way that the effect of qualifications in enterprises side is divided into an economic effect (improvement of productivity, improvement of qualifies of products) and non-economic effect (credibility on the job, expertise on techniques, assessment criteria on entrepreneurial value, applicability of job arrangement). Then, survey was carried out with questions designed in accordance with this model. The hypotheses were proved as the following. First, fir hypothesis 1(Environmental qualifications will bring up positive impacts on the economic effect of enterprises), it turned out to be true. The improvement of productivity and qualities of products were chose to represent the economic effect of entrepreneurs, and the both factors appeared to have positive impacts on the economic effect of enterprises. Second, for hypothesis 2(Environmental qualifications will have positive impacts on the non-economic effect of enterprises), it turned out to be true. Environmental qualifications were proved to have positive impacts on credibility on the job, expertise on techniques, assessment criteria on entrepreneurial value, applicability of job arrangement, which were introduced to represent the non-economic effect of enterprises. In conclusion, environmental qualifications were proved to have positive impacts on both economic and non-economic effect of enterprises.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.351-357
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• 2013

In flip chip packaging, underfill process is used to fill epoxy bonder into the gap between a chip and a substrate in order to improve the reliability of electronic devices. Underfill process by capillary motion can give rise to unwanted air void formations since the arrangement of solder bumps affects the interfacial dynamics of flow meniscus. In this paper, the unsteady flows in the capillary underfill process are visualized and then the racing effect and merging of the meniscus are investigated according to the arrangement of solder bumps. The result is shown that at higher bump density, the fluid flow perpendicular to the main direction of flow becomes stronger so that more air voids are formed. This phenomenon is more conspicuous at a staggered bump array than at a rectangular bump array.

• Journal of the Korean Applied Science and Technology
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• v.20 no.3
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• pp.268-273
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• 2003

IASL(iodo acetamide spin label) and MSL(maleimide spin label) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. The muscle was isometrically tetanized with three trains of 3ms pulses every 50ms between $5^{\circ}C$ with $25^{\circ}C$. Equatorial reflection change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of $143{\AA}$ and $72{\AA}$ could offer information of the mass projection of population of myosin head along the filament axis. The slope of intensity profile of the mass projection of $143{\AA}$ and reflection of IASL is appeared and that of MSL is appeared sharply. The decrease of $215{\AA}$ reflection intensity the periodical character of $143{\AA}$ reflection by spin label. The raise of MSL actin reflection at $51{\AA}$ and $59{\AA}$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we can conclude that IASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• Interaction and multiscale mechanics
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• v.2 no.4
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• pp.397-411
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• 2009

The effect of soil-structure interaction on a simple single storeyed and two bay space frame resting on a pile group embedded in the cohesive soil (clay) with flexible cap is examined in this paper. For this purpose, a more rational approach is resorted to using the three dimensional finite element analysis with realistic assumptions. The members of the superstructure and substructure are descretized using 20 node isoparametric continuum elements while the interface between the soil and pile is modeled using 16 node isoparametric interface elements. Owing to viability in terms of computational resources and memory requirement, the approach of uncoupled analysis is generally preferred to coupled analysis of the system. However, an interactive analysis of the system is presented in this paper where the building frame and pile foundation are considered as a single compatible unit. This study is focused on the interaction between the pile cap and underlying soil. In the parametric study conducted using the coupled analysis, the effect of pile spacing in a pile group and configuration of the pile group is evaluated on the response of superstructure. The responses of the superstructure considered include the displacement at top of the frame and moments in the superstructure columns. The effect of soil-structure interaction is found to be quite significant for the type of foundation used in the study. The percentage variation in the values of displacement obtained using the coupled and uncoupled analysis is found in the range of 4-17 and that for the moment in the range of 3-10. A reasonable agreement is observed in the results obtained using either approach.

• Journal of the Korean Society for information Management
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• v.39 no.2
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• pp.61-86
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• 2022

The purpose of this study is to investigate the effect of learning space Servicescape on the user satisfaction level and continuance intention and to identify moderating effect of the learning activity. The six Servicescape factors are selected after literature review and in-depth interviews; cleanliness, comfort, convenience, aesthetics, accessibility, and flexibility. The online survey is given to the university students at four-year private universities in Seoul metropolitan area. The result shows that among the learning space Servicescape factors, cleanliness, comfort, convenience, and accessibility have a significant impact on the user's satisfaction and the user's satisfaction response determines the continuance intention to the learning space. It is also found that the factors of cleanliness and comfort have a negative moderating effect on user satisfaction. This study implies that the result provides methods to develop the space arrangement for university libraries that provide the better-support to students' learning experience.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3
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• pp.113-120
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• 2006

This paper is concerned with a equalization technique for Orthogonal Frequency Division Multiplexing (OFDM) systems based on a block type pilot arrangement over slow fading channels. The bit rates obtained in underwater channels are relatively modest compared to some other communication channels such as cellular phones or indoor wireless systems. Consequently. the Doppler effect is the important parameter in tracking a channel. In case of a coherent demodulation scheme, the residual mean phase errors due to Doppler frequency may be fatal for the performance of the system. The equalizer could not solely handle mean Doppler shift. To account for the common Doppler effect a phase error tracking loop is used with the frequency equalizer. so that the rotation errors are avoided. Furthermore. simulations show that we can reduce the computational load of the tracking loop with negligible effect on performance.

• The Korean Journal of Community Living Science
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• v.18 no.1
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• pp.147-160
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• 2007

This research challenges the general notion of one-person households of the elderly during widowhood as impoverished, isolated, and vulnerable. Recognizing a high potential vulnerability, however, this research attempts to describe the diverse composition of one-person households of the elderly. For this purpose, relying on 2% sample data from the 2000 census, it examines regional distribution, socio-economic characteristics, and determinants of one-person households of the elderly during widowhood. Socio-economic characteristics of one-person households of the elderly differ by region. Jeju island is distinct in terms of sex and age distribution, and residence area of children. In general, rates of economic activity and self-subsistence are higher in provinces than in cities. Compared to the elderly living with family, the elderly living alone show high rates of economic activity, self-subsistence, and capability of physical activity. Results of logistic regression analysis of determinants of living arrangement are consistent with those of descriptive statistics. Those who are economically active and able to move around without assistance tend to live alone after the death of a spouse. Number of sons and living in an urban area are negatively associated with living alone, whereas females are more likely than males to live alone. According to the separate analysis by age, the positive effect of economic activity is greater in the oldest of the old than in other age groups. Those who possess high educational attainment tend to live alone when they are 80 and older, unlike other age groups. Based on these findings, this paper finds that one-person households of the elderly nay not always be the most vulnerable group, and are diverse in terms of socioeconomic characteristics.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.325-332
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• 2005

As ship builder companies have a tendency to pursuit the effect of scale economy, recently the ultra-large sized container ship is discussed very actively among them. It is expected that these situation will be continued for the time being. The need of accommodation re-arrangement is carefully proposed according to the tendency of ultra-large sized ship. In this paper, accommodation re-arrangement of ultra-large container ship is examined in the view of economy. We proposed separation of engine room and accommodation part through review and supplementaition of drawing generation in intial design stage. Also we investigated its merits and demerits to find out whether it can be realized or not in the view of economical efficiency. The RFR(Required Freight Rate) is considered as the objective function to evaluate the re-designed vessel. The economical benefits for increasing the number of TEU(Twenty-foot Equivalent Units)'s and the re-arranged space are analyzed in the view of ship owner and shipyards respectively.

• Journal of Labour Economics
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• v.24 no.1
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• pp.67-96
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• 2001

The recent economic crisis started at the end of 1997 has brought about changes in labor market practices. One of them is rapid increase in the ratio of workers with alternative employment arrangement, so-called contingent workers. This type of arrangement, unlike traditional employment arrangement, makes employers properly adjust employment to business cycles and it also makes it possible for employees to solve time and spatial constraints related to labor supply. However, recent experience has revealed its negative characteristics such as lower wage rate, deficient fringe benefits, insufficient job security. Using the data from the first and the second wave of the Korea Labor and Income Panel Survey, this study focuses on change in the tendency of being contingent workers and decomposition of the wage differentials among regular and contingent workers by estimating the switching regression model. Results show that the recent crisis significantly contributed to probabilities of being contingent workers, especially for women, the young, the older, and the lowly educated. Decomposition shows that one quarter or one third of 35% of wage differentials are due to the price effect that the same productive characteristics are differently paid by the types of employment arrangements.