• Clinical and Experimental Pediatrics
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• v.46 no.4
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• pp.370-375
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• 2003

Purpose : It has been suggested that the exposure to aeroallergens during early infancy after birth is important in the subsequent development of sensitization and allergic diseases. In Korea, the level of house dust mites as one of the important aeroallergens is known to be the highest in autumn. The aim of this study was to test whether the distribution of month of birth bears a relationship to the presence of mite sensitization in children with respiratory allergy. Methods : Skin prick tests and methacholine provocation tests were performed on 1,327 patients with chronic respiratory symptoms who visited Seoul National University Children's Hospital from January 1995 to May 2002. An analysis of patients' month of birth distribution according to the presence of mite sensitization was performed. Results : Atopic subjects who had at least one positive skin test numbered 864(65.1%); and non-atopic subjects numbered 463(34.9%). Among atopic subjects, 787(59.3%) had positive skin tests to mites and 77(5.8%) had positive skin test only to minor allergens. A significantly greater than expected number of mite atopic subjects were born in the months between August and November(P=0.03), however, the birth month of non-atopic subjects didn't show a consistent seasonal preference. Asthma patients numbered 543(40.9%). Among these, atopic asthmatics numbered 421(77.5%) and non-atopic asthmatics, 122(22.5%). Dust-mite atopic asthmatics numbered 387(91.9%) out of 421 atopic asthmatics. Dust-mite atopic asthmatics were born significantly higher in the season lasting from August to November in comparison to non-atopic asthmatics(P=0.002). Conclusion : Month of birth seems to be related with sensitization to allergens. Our results show that August to November is the risk period for the development of mite sensitization in Korea.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.1-18
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• 2015

Collaborative filtering(CF) algorithm has been popularly used for recommender systems in both academic and practical applications. A general CF system compares users based on how similar they are, and creates recommendation results with the items favored by other people with similar tastes. Thus, it is very important for CF to measure the similarities between users because the recommendation quality depends on it. In most cases, users' explicit numeric ratings of items(i.e. quantitative information) have only been used to calculate the similarities between users in CF. However, several studies indicated that qualitative information such as user's reviews on the items may contribute to measure these similarities more accurately. Considering that a lot of people are likely to share their honest opinion on the items they purchased recently due to the advent of the Web 2.0, user's reviews can be regarded as the informative source for identifying user's preference with accuracy. Under this background, this study proposes a new hybrid recommender system that combines with users' review mining. Our proposed system is based on conventional memory-based CF, but it is designed to use both user's numeric ratings and his/her text reviews on the items when calculating similarities between users. In specific, our system creates not only user-item rating matrix, but also user-item review term matrix. Then, it calculates rating similarity and review similarity from each matrix, and calculates the final user-to-user similarity based on these two similarities(i.e. rating and review similarities). As the methods for calculating review similarity between users, we proposed two alternatives - one is to use the frequency of the commonly used terms, and the other one is to use the sum of the importance weights of the commonly used terms in users' review. In the case of the importance weights of terms, we proposed the use of average TF-IDF(Term Frequency - Inverse Document Frequency) weights. To validate the applicability of the proposed system, we applied it to the implementation of a recommender system for smartphone applications (hereafter, app). At present, over a million apps are offered in each app stores operated by Google and Apple. Due to this information overload, users have difficulty in selecting proper apps that they really want. Furthermore, app store operators like Google and Apple have cumulated huge amount of users' reviews on apps until now. Thus, we chose smartphone app stores as the application domain of our system. In order to collect the experimental data set, we built and operated a Web-based data collection system for about two weeks. As a result, we could obtain 1,246 valid responses(ratings and reviews) from 78 users. The experimental system was implemented using Microsoft Visual Basic for Applications(VBA) and SAS Text Miner. And, to avoid distortion due to human intervention, we did not adopt any refining works by human during the user's review mining process. To examine the effectiveness of the proposed system, we compared its performance to the performance of conventional CF system. The performances of recommender systems were evaluated by using average MAE(mean absolute error). The experimental results showed that our proposed system(MAE = 0.7867 ~ 0.7881) slightly outperformed a conventional CF system(MAE = 0.7939). Also, they showed that the calculation of review similarity between users based on the TF-IDF weights(MAE = 0.7867) leaded to better recommendation accuracy than the calculation based on the frequency of the commonly used terms in reviews(MAE = 0.7881). The results from paired samples t-test presented that our proposed system with review similarity calculation using the frequency of the commonly used terms outperformed conventional CF system with 10% statistical significance level. Our study sheds a light on the application of users' review information for facilitating electronic commerce by recommending proper items to users.

• Journal of The Korean Association For Science Education
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• v.25 no.4
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• pp.441-449
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• 2005

The purpose of this study was to examine the degree of cognitive conflict by learner personality and the method of presenting anomalous data to induce cognitive conflict. The participants of this study were 461 high school students. To arose cognitive conflict, an actual demonstration was done for half of the participants and a logical article for the rest. MBTI (Myers-Briggs Type Indicator) was used to find the learner personality types, and CCLT (Cognitive Conflict Level Test) was used to measure the degree of cognitive conflict aroused when anomalous data was confronted. The results of this study indicated that learner personality types influence the degree of cognitive conflict. First, participants were divided into two personality types via preferences on each of the four preference indices; extraversion (E) or introversion (I), sensing (S) or intuition (N), thinking (T) or feeling (F), judgment (J) or perception (P). The cognitive conflict scores of the thinking types were significantly higher than those of the feeling types. Participants were also divided four personality types according to personality functional types: ST, SF, NT and NF. SF type showed a significantly lower cognitive conflict score than any of the other types. According to the type of learner personality, cognitive conflict was influenced differently by the method of presenting anomalous data. For example, the judgment types had a higher cognitive conflict score by logical argument, and the perception types showed a higher score by demonstration. In conclusion, learner cognitive conflicts were influenced by personality types and the methods of presenting anomalous data.

• Research in Community and Public Health Nursing
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• v.9 no.1
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• pp.143-162
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• 1998

This is a study for the construction of nursing care based upon the Korean attitude toward medicine. Factors which were investigated include the source of nursing care, the reason for choosing care, the type of heath care chosen, the accessability of caregivers, and the desired location of death. The population examined in this study consisted of 517 adults distributed in six large cities and 191 adults from five rural communities. Data was analyzed using frequency, percent, Cronbach alpha, $X^2$ - test, t - test, F - test and scheffe post hoc contrast with an SAS program. The results of this study are summarized as follows: 1. Among sources of nursing care used, first rank rated-pharmacy(54.4), private hospital(18.2), general hospital(8.4), folk remedies in house (5.0), chinese hospital(2.8), prayer(2.8) and others(8.4), and the reasons for choosing nursing care rated 'the easiest method' (63.6), 'the best method'(15.7), 'reliable'(10.8) and 'lower cost burden'(4.6) in order of preference. 2. The type of nursing care chosen rated western medicine(6.80), chinese medicine(6.15), folk remedies(5.46), faith remedies(3.51) and divination remedies (1.41). There were significant differences in the effect recognition degree to various kinds of medicine. 3. The difference of the type of nursing care chosen according to general characteristics showed that urban residents were higher than rural community residents(t=2.15, p=0.0320) in western medicine, and urban residents, women, and singles were higher than rural community residents(t=2.04, p=0.0414), men (t= -2.89, p=0.0039), and married(t=2.50, p= 0.0126) on folk remedies. With repect to age and education those 21-30, under 20 and 31-40, graduated from college and graduate school were higher than above 51, above 61 (F = 7.76, p = 0.0001), graduated from elementary school(F=4.39, p=0.0006) on folk remedies. In other categories, rural community residents, women, younger people. Christians were higher than urban residents ( t = -2.73, p=0.0305), men(t= -4.15, p=0.0001), older people (F=2.48, p=0.0307), Catholic, Buddhist, or atheist (F= 70.18, p=0.0001) on faith remedies. Those graduated from high school and Buddhist were higher than unschooled, graduated from middle school(F=3.18, p= 0.0075), atheist, Catholic or Christian(F=18.32, p=0.0001) on divination redemies. There were significant differences concerning age and education level. 4. The accessibility of caregivers rated 'caregivers should be nearby if the patients need them' (50.0), 'caregivers must be there all day (24 hours)' (39.6), 'caregivers must be there at night only'(5.0), 'caregivers must be there during the day only'(2.6), 'caregivers always should visit during visiting hours' 0.4), 'caregivers don't need to be there at all' (1.2). The frist rank of suitable caregivers were rated as spouse(66.6), mother(24.2), daughter (3.6), daughter-in-law(1.9), and the reasons of thinking thus were rated as 'the most comfortable' (81.5), 'people should correctly with regards to family they'(7.1), 'the easiest' (5.4), 'take good care of the patient' (5.1) and 'lower cost burden' (0.4). 5. The desired location of death rated as the following: his/her house (91. 6) to the hospital(8. 4). A person going to encounter death in the hospital wanted his house(78.5) over the hospital(21.5), and a person dieing in the hospital prefered his house(52.9) over the hospital(47.1) as a funeral ceremony place. The following suggestions are made based on the above results. 1. A sampling method that enhances the re presentativeness should be used in regional and/or national related research and replicated to confirm the result of this study. 2. This study should be used to understand the Korean view of medical centers and to meet the expectations of patients in Korean nursing. 3. Research on the Korean traditional view of humans and expectations of the sick, health and illness, and health behavior, the perception of dying, the decision to heal, and the view of general medicine should continue to be conducted continuosly so that Korean nursing theory can be advanced on these concepts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1753-1759
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• 2009

The present study was conducted to investigate the effects of components obtained from Zanthoxylum schinifolium and Zanthoxylum piperitum on rancidity and quality of Kwamegi (semi-dried Pacific saury, Coloabis saira). Ethanol extract (ZS) of Zanthoxylum schinifolium leaves or the essential oil (ZP) obtained from pericarp of Zanthoxylum piperitum in 1 or 20% ethanol solution was sprayed to the Pacific saury before Kwamegi preparation at its final concentrations of 0.125~2 ppm in the Kwamegi. The prepared Kwamegi was vacuum packed with multi-layered film (polyethylene/polyamide/EVOH/polyethylene, thickness 80 μm) and kept at -20${^{\circ}C}$ until use. After opening the package Kwamegi was stored at 4${^{\circ}C}$ for 1, 3 and 7 days during which rancidity tests and sensory evaluation were carried out. Acid, peroxide, and thiobarbituric acid (TBA) values increased with storage time but reduced significantly by the addition of ZS at the concentrations of ≥G0.125 ppm and ZP≥F0.25 ppm. The effects of ZS and ZP were dose-dependent and more pronounced as storage time prolonged. The ZS and ZP also reduced dimethyamine and trimethyamine (TMA) contents which were increased with time, while they prevented the decrease of trimethyamine oxide. The ZS at the concentration of ≥G0.25 ppm and the ZP at >0.5 ppm were needed to maintain TMA less than 4.5 mg/100 g for 3 day storage at 4${^{\circ}C}$. Sensory evaluation of the Kwamegi exhibited a slightly higher preference with the ZS and ZP treated ones at the level of 0.25~0.5 ppm. It is concluded that very low amounts of ZS and ZP are effective in suppression of rancidity of Kwamegi and could be utilized for its quality management.

• Korean journal of food and cookery science
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• v.23 no.6
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• pp.848-857
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• 2007

Sikhe, a traditional Korean drink, was prepared with Hovenia dulcis extract (HDE), and its quality and storage characteristics were evaluated through sensory and microbial analyses. In the color analysis, the lightness of the Sikhe showed a decreasing tendency according to the addition of HDE, while redness and yellowness increased. The Sikhe prepared with 20% HDE had the highest sugar concentration at 12days of storage ($4^{\circ}C$). Interms of sensory quality, both the 20% and 40% HDE-added Sikhes had the highest overall preference. The microbial cell counts presented no distinct differences early in the storage. period, but the general bacteria counts of the Sikhe made with the increasing concentrations of extracts decreased with a longer storage period. The coliform counts of the Sikhe prepared without HDE (control) was 10.5 CFU/g at 10 days of storage, but the 100% HDE-added Sikhe had a level of 7.9 CFU/g at 16 days of storage. These results indicates that Hovenia dulcis may inhibit normal microbial growth and extend the shelf-life on Sikhe.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.43-50
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• 2002

To develop commercial semi-solid apple baby food, the physicochemical characteristics of apple puree in relation to different preparing methods and the effect of the addition methods of ascorbic acid on browning reaction were investigated. The preparing methods were classified into 3 groups by initial heating treatment: no heating (A), steaming at $120^{\circ}C$ (B), and blancing at $100^{\circ}C$ (C). The viscosity of tested apple puree was $2,600{\sim}5,856\;cp$, and contents of anhydrogalaturonic acid (AGA) and neutral sugar ranged $4.15{\sim}11.92\;mg%$ and $6.18{\sim}10.65\;mg%$, respectively. Among free sugars tested, level of fructose was the highest $(5.43{\sim}8.87%)$, followed by glucose $(2.11{\sim}4.23%)$, sucrose $(1.64{\sim}2.94%)$, in that order. Since small amounts of ascorbic acid were detected $(1.54{\sim}1.83\;mg%)$, it seemed to be lost by heating process in preparing of apple puree. For apple puree A, its lightness was lower and redness was higher than those of apple puree B and C. Its degree of browning of apple puree was so high that sodium ascorbic acid was added as a antibrowning agent. Puree had low sensory score and nutrient quality. The adding methods of ascorbic acid were classified into 4 groups by adding time: dipping, blending (2), heating (3), and blending + heating (4). Considering color and preference evaluation, preparing method B and adding method 2 showed the highest inhibitory activity on apple puree browning and desirable color for retort baby food. After retort sterilization, the viscosity of apple baby food was decreased from 3,477 cp to 2,294 cp, thiamin was destroyed completely, and the contents of riboflavin and ascorbic acid were decreased 41% and 21%, respectively. However, contents of free sugar and free amino acid and sensory parameter were not influenced by retort sterilization. In overall, the preparing method B-adding method 2 was a good processing condition for the retort apple baby food.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.111-117
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• 2007

This experiment was conducted to research the effects of Yellow Clay(YC) on the sensory evaluation of cooked meat in broiler chicks. A total of 216 one day old broiler chicks were divided into 6 groups at random. The six groups are consisted of one control group, to which no YC was added, and 5 groups to which an amount of YC was differently added. Diets contained 0.5, 1.0, 2.0, 4.0 and 8.0% of YC and fed to the 5 group broilers for 6 weeks. The lightness of meat in the broilers treated with YC was significantly higher than that of the control group in after-cooking(P<0.05). Besides, the lightness of meat was higher after-cooking than before-cooking. The properties of hardness, gumminess and chewiness were significantly lowered in the groups treated with Yellow Clay, as the amount of Yellow Clay increased at before-cooking and after-cooking(P<0.05). The turbidity of stock was higher in the groups treated with Yellow Clay as the percentage level of Yellow Clay increased, compared with the control group(P<0.05). The acceptability of color, flavor, and texture of meat and stock was higher in the groups treated with Yellow Clay, when compared with that of the control group(P<0.05). In total, the group treated with the 4 percentage of Yellow Clay was the highest in the overall preference(P<0.05).

• Journal of the Korean Society of School Health
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• v.12 no.2
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• pp.207-215
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• 1999

The objectives of this study are to explain the use of media materials in school health education with other related factors in elementary, middle, and high schools in Korea. The data were collected by questionnaires from June to September in 1998. The number of subjects were 294 school nurses. The PC-SAS program was used for statistical analysis such as percent distribution, chi-squared test, spearman correlation test, and logistic regression. The use of media materials in health education has become extremely common. Unfortunately, much of the early materials were of poor production quality, reflected low levels of interest, and generally did little to enhance health education programming. A recent trend in media materials is a move away from the fact filled production to a more affective, process-oriented approach. There is an obvious need for health educators to use high-quality, polished productions in order to counteract the same levels of quality used by commercial agencies that often promote "unhealthy" lifestyles. Health educators need to be aware of the advantages and disadvantages of the various forms of media. Selecting media materials should be based on more than cost, availability, and personal preference. Selection should be based on the goal of achieving behavioral objectives formulated before the review process begins. The decision to use no media materials rather than something of dubious quality usually be the right decision. Poor-quality, outdated, or boring materials will usually have a detrimental effect on the presentation. Media materials should be viewed as vehicles to enhance learning, not products that will stand in isolation. Process of materials is an essential part of the educational process. The major results were as follows : 1. The elementary schools used the materials more frequently. But the production rate of media materials was not enough. The budget was too small for a wide use of media materials in school health education. These findings suggest that all schools have to increase the budget of health education programs. 2. Computers offer an incredibly diverse set of possibilities for use in health education, ranging from complicated statistical analysis to elementary-school-level health education games. But the use rate of this material was not high. The development of related software is essential. Health educators would be well advised to develop a basic operating knowledge of media equipment. 3. In this study, the most effective materials were films in elementary school and videotapes in middle and high school. Film tends to be a more emotive medium than videotape. The difficulties of media selection involved the small amount of extant educational materials. Media selection is a multifaceted process and should be based on a combination of sound principles. 4. The review of material use following student levels showed that the more the contents were various, the more the use rate was high. 5. Health education videotapes and overhead projectors proved the most plentiful and widest media tools. The information depicted was more likely to be current. As a means to display both text and graphic information, this instructional medium has proven to be both effective and enduring. 6. An analysis of how effective the quality of school nurse and school use of media materials shows a result that is not complete (p=0.1113). But, the budget of health education is a significant variable. The increase of the budget therefore is essential to effective use of media materials. From these results it is recommended that various media materials be developed and be wide used.

• KDI Journal of Economic Policy
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• v.13 no.4
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• pp.31-57
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• 1991

Korean firms of all sizes, from virtually every industry, have used and are using the term "excessive competition" to describe the state of their industry and to call for government interventions. Moreover, the Korean government has frequently responded to such calls in various ways favorable to the firms, such as controlling entry, curbing capacity investments, or allowing collusion. Despite such interventions' impact on the overall efficiency on the Korean economy as well as on the wealth distribution among diverse groups of economic agents, the term "excessive competition", the basis for the interventions, has so far escaped rigorous scrutiny. The objective of this paper is to clarify the notion of "excessive competition" and "over-investment" which usually accompanies "excessive competition", and to examine the circumstances under which they might occur. We first survey the cases where the terms are most widely used and proceed to examine those cases to determine if competition is indeed excessive, and if so, what causes "excessive competition". Our main concern deals with the case in which the firms must make investment decisions that involve large sunk costs while facing uncertain demand. In order to analyze this case, we developed a two period model of capacity precommitment and the ensuing competition. In the first period, oligopolistic firms make capacity investments that are irreversible. Demand is uncertain in period 1 and only the distribution is known. Thus, firms must make investment decisions under uncertainty. In the second period, demand is realized, and the firms compete with quantity under realized demand and capacity constraints. In the above setting, we find that there is "no over-investment," en ante, and there is "no excessive competition," ex post. As measured by the information available in period 1, expected return from investment of a firm is non-negative, overall industry capacity does not exceed the socially optimal level, and competition in the second period yields an outcome that gives each operating firm a non-negative second period profit. Thus, neither "excessive competition" nor "over-investment" is possible. This result will generally hold true if there is no externality and if the industry is not a natural monopoly. We also extend this result by examining a model in which the government is an active participant in the game with a well defined preference. Analysis of this model shows that over-investment arises if the government cannot credibly precommit itself to non-intervention when ex post idle capacity occurs, due to socio-political reasons. Firms invest in capacities that exceed socially optimal levels in this case because they correctly expect that the government will find it optimal for itself to intervene once over-investment and ensuing financial problems for the firms occur. Such planned over-investment and ensuing government intervention are the generic problems under the current system. These problems are expected to be repeated in many industries in years to come, causing a significant loss of welfare in the long run. As a remedy to this problem, we recommend a non-intervention policy by the government which creates and utilizes uncertainty. Based upon an argument which is essentially the same as that of Kreps and Wilson in the context of a chain-store game, we show that maintaining a consistent non-intervention policy will deter a planned over-investment by firms in the long run. We believe that the results obtained in this paper has a direct bearing on the public policies relating to many industries including the petrochemical industry that is currently in the center of heated debates.