• Journal of the Korea Society of Computer and Information
• /
• v.14 no.11
• /
• pp.233-245
• /
• 2009

The number of subscribers and the level of service usage are moderately low though WiBro service, as a new mobile Internet service, has been provided to mobile Internet users since June 2006. Considering this situation, the study was to identify, in exploratory point of view, which critical success factors are considered by mobile Internet users as the most important one to facilitate WiBro service, and to examine the perception of critical success factors of WiBro service varies according to their demographic characteristics. The study also was to suggest a few of research propositions on the relationships between critical success factors of WiBro service and characteristics of mobile Internet users, based on various statistical analyses. To accomplish these research purposes, the study defined research variables such as demographic characteristic of mobile Internet users, types of user, and critical success factors of WiBro service based on the review of mobile Internet service related studies. And then, the study performed various statistical analyses using survey questionnaires on mobile Internet users. The analyses show that there are little differences in perception on critical success factors of WiBro service among the mobile Internet users grouped by job and residential region, and that only the relationship between occupation of mobile Internet users and critical success factors of WiBro service is moderated by the types of user. Finally, the study proposed some research propositions, based on these analysis results, that could be used in the future studies.

• Journal of Biosystems Engineering
• /
• v.37 no.4
• /
• pp.258-264
• /
• 2012

Purpose: This review aims at introducing 3 modeling approaches classified into 3 categories based on the purpose (estimation or prediction), structure (linear or non-linear) and phase (steady-state or dynamic-state); 1) statistical approaches, 2) kinetic modeling and 3) mechanistic modeling. We hope that this review can be a useful guide in the model-based approach of calcium metabolism as well as illustrates an application of engineering tools in studying biosystems. Background: The meaning of biosystems has been expanded, including agricultural/food system as well as biological systems like genes, cells and metabolisms. This expansion has required a useful tool for assessing the biosystems and modeling has arisen as a method that satisfies the current inquiry. To suit for the flow of the era, examining the system which is a little bit far from the traditional biosystems may be interesting issue, which can enlarge our insights and provide new ideas for prospective biosystem-researches. Herein, calcium metabolic models reviewed as an example of application of modeling approaches into the biosystems. Review: Calcium is an essential nutrient widely involved in animal and human metabolism including bone mineralization and signaling pathways. For this reason, the calcium metabolic system has been studied in various research fields of academia and industries. To study calcium metabolism, model-based system analyses have been utilized according to the purpose, subject characteristics, metabolic sites of interest, and experimental design. Either individual metabolic pathways or a whole homeostasis has been modeled in a number of studies.

• The Journal of the Korea Contents Association
• /
• v.12 no.10
• /
• pp.466-479
• /
• 2012

Temple stay has increased fast in the quantitative part recently and it is tourism goods with cultural value as a kind of religion tourism. It is thought that the qualitative development is accompanied with quantitative development at this time. So, in order to increase qualitative improvement, it is needed to confirm mutual relationships among religious involvement, satisfaction factors of performance and behavior intentions of people who takes part in temple stay. Also, this paper confirms whether statistical characteristic of population affects religious involvement or not. 3 assumptions are established for these purposes and all of 3 established assumptions are partly adopted through statistical analyses.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.3
• /
• pp.339-345
• /
• 2018

Sunrise and sunset times differ depending on location and date. Previous studies conveniently but monotonously applied day and night times set up. This research defined the daytime and nighttime while considering the time of twilight according to the date and the location of ship collision accidents. Classifying the frequency of ship collision accidents with this standard, we conducted a chi-squared test for the difference between daytime and nighttime. The frequencies of ship collision accidents according to daytime and nighttime was compared by season, month, and time, and all of them showed statistically significant differences. The highest number of daytime ship collisions was 11.6 %, in June, and nighttime collisions peaked at 13.7 %, in December. The most frequent hour for daytime ship collisions was 0700h-0800h, at 10.2 %, and nighttime collisions peaked between 0400h-0500h, at 16.9 %. It is clear that the criteria used in previous studies cited was applied without any theoretical basis and likely only for the convenience of the researchers. It was found that results depend on what criteria are applied to the same research data. This study shows that statistical analyses of marine accidents, traffic volume, and congestion density should be carried out quantitatively while considering daytime and nighttime hours for each particular location and date.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.7
• /
• pp.910-914
• /
• 2001

The teat number of a sow plays an important role for weaning pigs and has been utilized in selection of swine breeding stock. Various linear models have been employed for genetic analyses of teat number although the teat number can be considered as a count trait. Theoretically, Poisson error mixed models are more appropriate for count traits than Normal error mixed models. In this study, the two models were compared by analyzing data simulated with Poisson error. Considering the mean square errors and correlation coefficients between observed and fitted values, the Poisson generalized linear mixed model (PGLMM) fit the data better than the Normal error mixed model. Also these two models were applied to analyzing teat numbers in four breeds of swine (Landrace, Yorkshire, crossbred of Landrace and Yorkshire, crossbred of Landrace, Yorkshire, and Chinese indigenous Min pig) collected in China. However, when analyzed with the field data, the Normal error mixed model, on the contrary, fit better for all the breeds than the PGLMM. The results from both simulated and field data indicate that teat numbers of swine might not have variance equal to mean and thus not have a Poisson distribution.

• The Korean Journal of Applied Statistics
• /
• v.10 no.2
• /
• pp.227-239
• /
• 1997

PLSR is a powerful multivariate statistical tool that has been successfully applied to the quantitative analyses of data in spectroscopy, chemistry, and industrial process control. Data in spectorscopy is represented by spectrum matrix measured in many wavelengths. Problems of many kinds of noise in data and itercorrelation between wavelengths are quite common in such data. PLSR utilizes whole data set measured in many wavelengths to the analysis, and handles such problems through data compression method. We investigated the PLSR theory, and applied this method to the data for spectroscopic diagnosis of Total Hemoglobin in whole blood.

• Journal of the Korean Society of Costume
• /
• v.51 no.4
• /
• pp.31-42
• /
• 2001

The purpose of this study was to develop a large representative data base for character goods marketing strategy. The study was to determine character name awareness in relation to segmented distribution regions and such demographic variables as sex and age. The author also analyzed preferred design. A total of 360 questionnaires were distributed and 359 reliable ones were used for statistical analysis. A SAS statistical package including frequency tables and Chi square test and factor analysis and Kendall′s relation analyses was used. The results are as follow : character name awareness involves "character name decognition" based on asking subjects to identify character names from 50 given names. "Tele-tubbies" was found to be a dominant commercial character name as a result of the recognition test, and "Sailer-moon" was found to be a dominant animation character goods as a result of the recognition test. Character recognition was significantly different in the segmented distribution legions, three age groups and different sex groups. People considered design first in purchasing any character goods, and they considered color second in purchasing them. The most favored part of garment far character to be stitch to was the center front in the T-shirt/dress shirt, the center back in the Jumper/jacket, back pocket in the trousers/skirt. The results of a Chi-square test showed that preferred part in the trousers/skirt of character was related with age variables.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2005.09a
• /
• pp.249-255
• /
• 2005

Angiotensin-converting enzyme (ACE) is primarily responsible for human hypertension. Current ACE drugs show serious cough and angiodema health problems due to the un-specific activity of the drug to ACE protein. The availability of ACE crystal structure (1UZF) provided the plausible biological orientation of inhibitors to ACE active site (C-domain). Three-dimensional quantitative structure-activity relationship (3D-QSAR) models have been constructed using the comparative molecula. field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) for a series of 28 ACE inhibitors. Alignment for CoMFA obtained by docking ligands to 1UZF protein using FlexX program showed better statistical model as compared to superposition of corresponding atoms. The statistical parameters indicate reasonable models for both CoMFA (q$^2$ = 0.530, r$^2$ = 0.998) and CoMSIA (q$^2$= 0.518, r$^2$ = 0.990). The 3D-QSAR analyses provide valuable information for the design of ACE inhibitors with potent activity towards C-domain of ACE. The group substitutions involving the phenyl ring and carbon chain at the propionyl and sulfonyl moieties of captopril are essential for specific activity to ACE.

• The Korean Journal of Applied Statistics
• /
• v.11 no.1
• /
• pp.65-81
• /
• 1998

Simultaneous equation models, increasingly used in many detailed analyses, tend to get larger and more sophisticated to describe the structure of the study area to be close to the actual situations. In setting up such a system of equations, statistical results and simulation performance of the model as a whole may be meaningless and unrepresentative of the real world due to a structural instability that is built into the model when the equations are combined and solved simultaneously. Even though the use and subsequent analysis of an unstable system are likely to mislead us, most of the studies that take the simultaneous equation approaches neglect such a serious problem. Thus it is necessary to illustrate how to check the stability problem and apply to the actual model, then investigate how such as analysis is able to provide useful information about the structural characteristics of the model from the dynamic viewpoint.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.32 no.E
• /
• pp.67-73
• /
• 1990

Many distress mechanisms in pavement are known to be caused by the poor mechanical properties of bituminous concretes. Among many mechanical properties, tensile strength is one of the more important indicates that represent the resistance of pavement to traffic loading. However, there has been no relationship established between the strength and distress mechanisms. Therefore, this study was conducted to evaluate a correlation between the tensile strength value and the intensity of distress in bituminous concrete. Distress data were collected from an extensive field investigation over 77km of a four-lane highway in South Carolina, USA, and from laboratory prepared specimens in two phases of study. Strength data were obtained from a total of more than 400 field cores taken from the same highway and from 640marshall specimens of surface course mixture prepared in the laboratory. These data were analyzed using statistical test techniques. It was found from statistical analyses that the tensile strength of bituminous concrete had a strong relation with the pavement condition in the field. In the analysis of rutting and stripping, low strength concrete showed a higher distress rate in the mixture, and mixtures under distress in the field showed obviously reduced strength values. Stripping was found to be the most significant distress mechanism that was correlated with low strength bituminous concrete. Rutting appeared more frequently in a low strength pavement section of the highway as a sign of failure due to traffic loading.