• Asia pacific journal of information systems
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• v.17 no.4
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• pp.113-132
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• 2007

Price rigidity involves prices that do not change with the regularity predicted by standard economic theory. It is of long-standing interest for firms, industries and the economy as a whole. However, due to the difficulty of measuring price rigidity and price adjustments directly, only a few studies have attempted to provide empirical evidence for explanatory theories from Economics and Marketing. This paper proposes and validates a research model to examine different theories of price rigidity and to predict what variables can explain the observed empirical regularities and variations in price adjustment patterns of Internet-based retailers. I specify and test a model using more than 3 million daily observations on 385 books, 118 DVDs and 154 CDs, sold by 22 Internet-based retailers that were collected over a 676-day period from March 2003 to February 2005. I obtained a number of interesting findings from the estimation of our logit model. First, quality seems to play a role-I find that both price levels as proxies for store quality, and information on the quality of a product consumers have, affect online price rigidity. Second, greater competition(i.e., less industry concentration) leads to less price rigidity(i.e., more price changes) on the Internet. I also find that Internet-based sellers more frequently change the prices of popular products, and the sellers with broader product coverage change prices less frequently, which seem due to economic forces faced by these Internet-based sellers. To the best of my knowledge, this research is the first to empirically assess price rigidity patterns for multiple industries in Internet-based retailing, and attempt to explain the variation in these patterns. I found that price changes are more likely to be driven by quality, competitive and economic considerations. These results speak to both the IS and economics literatures. To the IS literature these results suggest we take economic considerations into account in more sophisticated ways. The existence and variation in price rigidity argue that simplistic assumptions about frictionless and completely flexible digital prices do not capture the richness of pricing behavior on the Internet. The quality, competitive and economic forces identified in this model suggest promising directions for future theoretical and empirical work on their role in these technologically changing markets. To the economics literature these results offer new evidence on the sources of price rigidity, which can then be incorporated into the development of models of pricing at the firm, industry and even macro-economic level of analysis. It also suggests that there is much to be learned through interdisciplinary research between the IS, economics and related business disciplines.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.745-751
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• 2006

The transmitter requires knowledge of the channel status information in order to adopt the adaptive modulation and coding scheme(AMC) for OFDM system. But in the outdoor environment which the users have high mobility, the channel status information from the users is outdated, so that it induces the degradation of system throughput and packet error rate(PER) performance. To solve this problem, researches about applying channel prediction technique to the AMC scheme have been proceeded. Most channel prediction techniques assume that there is no channel variation in the predefined time duration, e.g., a slot. As a result, those techniques cannot compensate the degradation of PER performance resulting from the rapid variation of channel during the slot duration. This paper introduces a novel channel prediction technique for OFDM/FDD system to support adaptive modulation and coding scheme over rapidly time-varying multipath fading channel. The proposed channel prediction technique considers the time-varying nature of channel during the slot duration. Simulation results show that the AMC scheme of OFDM/FDD system utilizing the proposed channel prediction technique can guarantee the target PER of 1% without any loss of system throughput compared with the case supported by the conventional channel prediction under ITU-R Veh A 30km/h.

• Journal of Korean Biological Nursing Science
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• v.5 no.1
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• pp.13-22
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• 2003

The purpose of this study was to investigate and analyze current educational requirements related to genetics curriculum(from June 2002 to September 2002) established at nursing institutions and to provide the basic data for the development of genetics science program at the undergraduate. Subjects of this study were comprised of twenty-three colleges of nursing in 4-year baccalaureate and thirty colleges in 3-year diploma programs. The results of this study were as follows : 1) 32 colleges offer courses related to genetics. 29 among 32 colleges have that integrated. Three schools have established completely independent courses of genetics. 21 colleges do not have any courses dealing with genetics. 2) The contents of courses related to genetics include: Congenital abnormalities, chromosomal aberrations, congenital metabolic disease, prenatal diagnosis and genetic counseling, genes and chromosomes, immune genetics, blood type and genetics, rule of genetics, variation in gene expression, the map of the human gene, gene linkage genetics, interaction of genes, single inheritance in order and genetic biochemistry. 3) For course credit, 14colleges(48.3%) offered at most 1 credit per course. The grade of student who can take the course, 51.7% were in their second year while 37.9% were in their third year. The majors of nursing faculty who taught the course were nursing(51.7%) and basic nursing science(17.2%). 4) As far as the need of opening the courses related to genetics, 36 colleges(67.0%) have made a 'need', 12 schools(22.6%) state 'dose not need'. 711e reason for need were the following development of bio engineering, increase number of patients who are related to genetics, recognition of the need in clinical nursing. 7 schools(13.2%) agreed to offer independent course in genetics but 39 schools(73.6%) are in disagreement with that. When the school offers the course with other courses, 27 schools(50.0%) are opening basic nursing science and 14 schools(26.4%) are opening nursing as an integrated courses. If the name of course was either genetic nursing(34.0%) or genetics(28.3%), the credits for the course was one or 2 credits. 33 schools(62.3%) students were in the first or second years. 41 schools(84.9%), the majors of the faculty who had taught the course were either basic nursing science(35.8%), nursing(28.3%) or basic medicine(24.5%). The contents of the course should include in that order: Chromosome aberrations, prenatal diagnosis and genetic counseling, congenital metabolic disease, congenital abnormalities, genes and chromosomes, the rules of genetics, immune genetics, interaction of genes, variation in gene expression, etc. The results and discussions of the study indicate that the entire curriculums need to be investigated with respect to contents of education, nursing curriculums and name of courses because of the increasing need of knowledge related to genetics in the clinical practice.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.147-154
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• 2006

Surgical intervention in the posterior maxillary region requires detailed knowledge of maxillary sinus anatomy and the possible anatomical variations. This study evaluated the incidence, location of maxillary sinus septa by using radiographic (panoramic radiography and computed tomography) findings and comparison of panoramic radography with CT in antral anatomical variation. This study was based on data from 70 sinuses in partial dentate maxilla. The sample consisted of 61 patients(25 women and 36 men, with ages ranging between 19 and 77 years and a mean age of $49.4{\pm}11.3$ years) who were being treatment-planned to receive implant-supported restorations. First, the panoramic images were examined for the presence of antral septa by radiologist and examiner who don't know about CT findings. And incidence of antral septa was evaluated using an axial plane of CT image. The incidence of septa was compared between panoramic radiography and CT. The accuracy of the incidence was compared between radiologists and dentists. A total of 20 septa were found in 70 sinuses on CT image and the prevalence of one or more septa per sinus was found to be 28.6%. The assumed incidence of septa on panoramic radiography was $27.6%{\pm}2.2%$ in radiologist and $31.9%{\pm}5.8%$ in dentists. Erroneous diagnosis rate was 11.42% in radiologist and 15.96% in dentists. 40% of antral septa were located in the anterior(premolar) region, 30% of septa were located in the middle(first molar) and posterior(second molar) region separately. Prior to implant placement, it seems appropriate to consider panoramic radiography as a standard radiographic examination and periapical radiographs may be used to complete the findings in regions not sharply depicted in the panoramic radiograph. And cross-sectional imaging should be used in sites with severe bone loss and close proximity of the maxillary sinus.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.187-195
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• 2019

The needs for precise diagnostics and farm management-decision aids have increased to reduce the risk of climate change and environmental stress. Crop simulation models have been widely used to search optimal solutions for effective cultural practices. However, limited knowledge on physiological responses to environmental variation would make it challenging to apply crop simulation models to a wide range of studies. Advanced research facilities would help investigation of plant response to the environment. In the present study, the sunlit controlled environment chambers, known as Korean SPAR (Soil-Plant-Atmosphere-Research) system, was developed by renovating existing SPAR system. The Korean SPAR system controls and monitors major environmental variables including atmospheric carbon dioxide concentration, temperature and soil moisture. Furthermore, plants are allowed to grow under natural sunlight. Key physiological and physical data such as canopy photosynthesis and respiration, canopy water and nutrient use over the whole growth period are also collected automatically. As a case study, it was shown that the Korean SPAR system would be useful for collection of data needed for understanding the growth and developmental processes of a crop, e.g., soybean. In addition, we have demonstrated that the canopy photosynthetic data of the Korean SPAR indicate the precise representation of physiological responses to environment variation. As a result, physical and physiological data obtained from the Korean SPAR are expected to be useful for development of an advanced crop simulation model minimizing errors and confounding factors that usually occur in field experiments.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.443-454
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• 2014

This study designed to know subjective structure about clinical experience of adaptation of new nursing staffs in a general hospital and using Q-methodology. Using Q-methodology, 40 new nursing staffs sorted working a general hospital through personal interview. The statement positions on the sorting continuum were scored from +4(representing the highest level of agreement) through 0(at the neutral position on the continuum) through to -4(representing the highest level of disagreement). Factor analysis of the data was undertaken using PC QUANL program to determine if any patterns were discernible. The five types extracted all had eigenvalues greater than 1.0 and explained 62.38% of the variation in responses.: (1) New workload type, (2) Interest and responsibility type, (3) Improve the situation type, (4) Lack of knowledge and technology type, and (5) Excessive workload type. The significant differences found in the subjective structure of clinical experience of adaptation of new nursing staffs in ad general hospital. The findings of this study could contribute to the development of an effective programmes of education and personnel clinical practice strategies.

• Korean Journal of Community Nutrition
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• v.20 no.6
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• pp.447-459
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• 2015

Objectives: This study aimed to assess the improvement of teachers' sanitation performance and food distribution environment at Centers for children's food service management after a sanitation education program. Methods: The subjects were 119 teachers working at child care centers registered in the Daejeon Center for Children's Foodservice Management in Dongu and Jung-gu, Daejeon. The sanitation education was provided three times from March to August in 2014, and the survey questionnaires were distributed before and after the education. The sanitation status of food service environment of the centers was examined by ATP(adenosine-5'-triphosphate) bioluminescence. Results: After the sanitation education, the teachers showed higher levels of sanitation knowledge. Also, sanitation performance and recognition level of the importance of it significantly improved after the education program. The mean variation scores of importance and performance after the education were 0.14 and 0.23. According to the Importance-Performance Analysis (IPA) results of 26 sanitation attributes about the food service environment, the selection attributes with relatively low performance and importance were mostly distributed in the children's and distributer's personal hygiene management area. However, all attributes except using a personal water bottle and cup were moved to high performance and importance level. Also, the ATP examination results showed that the sanitation status of the food service environment was improved after the education program. Conclusions: The sanitation education program was effective in improving the recognition of the importance of sanitation and its performance with regard to food service management.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.193-198
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• 2014

Purpose: The present study was aimed to investigate the variation of soft palate morphology in different age and gender groups. The correlations of radiographic velar length (VL), velar width (VW), pharyngeal depth (PD), and Need's ratio with soft palate variants were also studied in the North Indian subpopulation. Materials and Methods: The study sample consisted of 300 subjects aged between 15 and 45 (mean: 31.32) years. The velar morphology on lateral cephalograms was examined and grouped into six types. The results obtained were subjected to a statistical analysis to find the correlation between variants of the soft palate with gender and different age groups. Results: The most frequent type of soft palate was leaf shaped (48.7%), and the least common was crook shaped (3.0%) among both the genders and various age groups, showing a significant correlation. The mean VL, VW, and PD values were significantly higher in males and significantly correlated with the types of soft palate. A significant correlation was observed between the mean VL, VW, PD, and Need's ratio with various age groups, showing an inconsistent pattern with an increase in age. The types of soft palate, gender, and Need's ratio were also significantly correlated, with an overall higher mean value of the Need's ratio among female subjects and the S-shaped soft palate. Conclusion: The knowledge of a varied spectrum of velar morphology and the variants of the soft palate help in a better understanding of the velopharyngeal closure and craniofacial anomalies.

• Ocean and Polar Research
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• v.35 no.3
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• pp.259-272
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• 2013

One of the factors influencing the climate around Korea is the oceanic-atmospheric variability in the tropical region between the eastern Indian and the western Pacific Oceans. Lack of knowledge about the air-sea interaction in the tropical Indo-Pacific region continues to make it problematic forecasting the ocean climate in the East Asia. The 'Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment (TIPEX)' is a program for monitoring the ocean circulation variability between Pacific and Indian Oceans and for improving the accuracy of future climate forecasting. The main goal of the TIPEX program is to quantify the climate and ocean circulation change between the Indian and the Pacific Oceans. The contents of the program are 1) to observe the mixing process of different water masses and water transport in the eastern Indian and the western Pacific, 2) to understand the large-scale oceanic-climatic variation including El Nino-Southern Oscillation (ENSO)/Warm Pool/Pacific Decadal Oscillation (PDO)/Indian Ocean Dipole (IOD), and 3) to monitor the biogeochemical processes, material flux, and biological changes due to the climate change. In order to effectively carry out the monitoring program, close international cooperation and the proper co-work sharing of tasks between China, Japan, Indonesia, and India as well as USA is required.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.1
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• pp.35-40
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• 2016

End milling process is one of the broadly used manufacturing process for precision machined parts and products. Machining performance is often limited by chatter vibration at the tool-workpiece interface. Chatter vibration is a type of machining self-excited vibration which originated from the variation in cutting forces and the flexibility of the machine tool structure. Even though lots of cutting tooling methods are developed and used in machining process, precise analysis of cutting tooling effect in view of chatter vibration behavior. This study presents numerical and experimental approaches to verify and effects of various cutting parameters to affect to chatter vibration stability. Acquired knowledge from this study will apply the optimal cutting conditions to improve a machining process.