• Journal of Preventive Medicine and Public Health
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• v.55 no.1
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• pp.80-87
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• 2022

Objectives: Dengue remains hyperendemic in Malaysia despite extensive vector control activities. With dynamic changes in land use, urbanisation and population movement, periodic updates on dengue transmission patterns are crucial to ensure the implementation of effective control strategies. We sought to assess shifts in the trends and spatial patterns of dengue in Kelantan, a north-eastern state of Malaysia (5°15'N 102°0'E). Methods: This study incorporated data from the national dengue monitoring system (eDengue system). Confirmed dengue cases registered in Kelantan with disease onset between January 1, 2016 and December 31, 2018 were included in the study. Yearly changes in dengue incidence were mapped by using ArcGIS. Hotspot analysis was performed using Getis-Ord Gi to track changes in the trends of dengue spatial clustering. Results: A total of 10 645 dengue cases were recorded in Kelantan between 2016 and 2018, with an average of 10 dengue cases reported daily (standard deviation, 11.02). Areas with persistently high dengue incidence were seen mainly in the coastal region for the 3-year period. However, the hotspots shifted over time with a gradual dispersion of hotspots to their adjacent districts. Conclusions: A notable shift in the spatial patterns of dengue was observed. We were able to glimpse the shift of dengue from an urban to peri-urban disease with the possible effect of a state-wide population movement that affects dengue transmission.

• Journal of the Korea Society of Computer and Information
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• v.28 no.8
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• pp.87-93
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• 2023

In this paper, we propose a system that accurately and efficiently determines forward head posture based on network learning by analyzing the user's skeletal posture. Forward head posture syndrome is a condition in which the forward head posture is changed by keeping the neck in a bent forward position for a long time, causing pain in the back, shoulders, and lower back, and it is known that daily posture habits are more effective than surgery or drug treatment. Existing methods use convolutional neural networks using webcams, and these approaches are affected by the brightness, lighting, skin color, etc. of the image, so there is a problem that they are only performed for a specific person. To alleviate this problem, this paper extracts the skeleton from the image and learns the data corresponding to the side rather than the frontal view to find the forward head posture more efficiently and accurately than the previous method. The results show that the accuracy is improved in various experimental scenes compared to the previous method.

• Restorative Dentistry and Endodontics
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• v.46 no.4
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• pp.47.1-47.9
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• 2021

Objectives: This study aimed to use a laboratory model to evaluate the efficacy of an experimental bleaching agent. Materials and Methods: The model used human extracted molars that were treated and measured for bleaching efficacy. Teeth (n = 50) were distributed into 5 groups: Negative control (NC): immersion in water for 8 hours; Nanofibers (NFs): Experimental titanium dioxide nanofibers with stirring and light activation for 8 hours; Whitestrips (WS): Crest 3D White Glamorous White Whitestrips, 2 applications daily for 30 minutes, 14 days; 1% hydrogen peroxide (HP) standard: 1% hydrogen peroxide for 8 hours; and 30% HP standard: 30% hydrogen peroxide for 8 hours. Instrumental measurements were performed using a spectrophotometer. Results were recorded at baseline, 1-day post-bleaching, and 1-week post-bleaching. Kruskal-Wallis procedure was used to determine differences in color change. Pearson correlation was used to evaluate the relationship between visual and instrumental measurements. Tests of hypotheses were 2-sided with alpha = 0.05. Results: There was no significant difference in color parameters (L1, a1, b1, and shade guide units [SGU]) at baseline (p > 0.05). There was a significant difference among the groups for overall color change (ΔE^*ab) and change in shade guide units (ΔSGU) at 1-day and 1-week post-bleaching (p < 0.05). The higher the HP concentration, the higher the color change as expressed in ΔSGU and ΔE^*ab. The negative control exceeded the perceptibility threshold of ΔE^* = 1.2 regardless of time point. NFs showed a decrease in chroma, but were not statistically different compared to the negative control. Conclusions: The laboratory model was successful in screening an experimental bleaching agent.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.177-186
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• 2024

Purpose : The purpose of this study was to use oral instruction and taping to induce abdominal draw-in in the previous study, but there is a lack of research on the comparison of effects. Therefore, in this study, we would like to study how the effect of oral instruction, taping, and no feedback can affect muscle activity when performing abdominal draw-in pier exercises. Methods : Before the experiment, group A trained piers and applied only draw-in piers, group B applied taping feedback, and group C were divided into three groups per week for six weeks, and three sets of contractions for five seconds per group were performed five times, and a minute break was provided between each exercise. As a measurement tool, a wireless surface electromyography (EMG) was used to measure surface electromyography (Telemyo-DTS, NORAXON, USA) that derives a synthetic unit of muscle using a surface electrode. For statistical processing of data, the analysis is performed using the SPSS/PC Version 25.0 statistical program for Windows, and the statistical significance level is a=.05 Results : First, the duration was somewhat shorter in order to more accurately compare the muscle activity of the core muscles. Therefore, future research needs to be research that can be exercises with precise biofeedback and taping applied over a longer period of time. Secondly, it is believed that there is no significant difference, since the subjects were studied in healthy young adult men and women, not patients. Thirdly, they could not control the daily life of the subjects. Through future research, it is necessary to analyze the correlation between muscle activity and abdominal muscle thickness by adding ultrasound in addition to muscle activity in various age groups. Conclusion : During draw-in bridge exercise according to feedback, the muscle activity of the back muscle increased, and there was no significant difference in the muscle activity of the back muscle according to each feedback. Therefore, both the feedback applied during the draw-in pier exercise and the control group are effective in changing the thickness of the abdominal muscles.

• Asia-Pacific Journal of Business
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• v.15 no.2
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• pp.207-222
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• 2024

Purpose - This study investigates whether the lagged price difference ratio between preferred and common stocks is related to the return and closing price of the preferred stock using three panel models. Design/methodology/approach - As a first step, we use a two-way fixed effect panel model with stationary preferred stock returns as a dependent variable. For robustness, we then apply the autoregressive distributed lag model (ARDL) and error correction model (ECM) with nonstationary closing prices of the preferred stocks as a dependent variable and compare the results of each model. The ARDL and ECM models provide an advantage of estimating a long-run equilibrium equation together if a long-run relationship exists between the two time-series variables compared to the fixed effect model. Findings - Our sample consists of 107 preferred stocks with at least four years of daily observations as of the end of December 2023. The coefficients of the error correction terms in the ARDL and ECM models are highly statistically significant, approximately -0.08. This indicates that the disequilibrium between the closing prices of common and preferred stocks adjusts by about 8% per day toward equilibrium. In all three models, the price difference ratio on day t-1 was statistically significant in explaining the preferred stock returns or closing prices on day t, implying that trading based on the previous day's price difference ratio is effective for one day. Research implications or Originality - Furthermore, the returns on preferred stocks are higher for firms with a lower proportion of foreign investors or a lower foreign market capitalization of preferred stocks. This suggests that foreign investors with informational advantages do not actively engage in profit-taking by trading preferred stocks, thus not narrowing the price difference. In summary, the recent surge in preferred stock prices is likely driven mainly by the irrational behavior of retail investors.

• Journal of the Korean Society of Food Culture
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• v.6 no.2
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• pp.185-197
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• 1991

An eating behavior research was done with 50 females at a buffet styled restaurant during their lunch time. Of the respondents, 52.0% were professional and 54.0% were graduate school graduates. Of the respondents, 58.0% of the company were friends and 24.0% were relatives. The average time period of eating was $93.0{\pm}23.4$ minutes. The average frequency of taking food was $4.0{\pm}1.1$ and the average frequency of taking food after satiety was $1.4{\pm}0.8$. It is significant that lower frequency of food consumption was directly proportional to the age groups of respondents. The average selected food items were $30.4{\pm}7.1$ out of 175 and the average weight of the consumed food was $995.0{\pm}240.9$ g. The older age group chose a similar number of food items, but the amount of each food item was considerably less than younger. So the younger the age group was, the more they ate. The average food items at one time was $7.1{\pm}2.2$ and the average food weight time was $233.7{\pm}69.7$ g. The percentage of respondents who evaluated themselves as 'ate too much' was 70.0% and those who evaluate themselves 'ate properly' was 14.0%. Most of them were satisfied with the buffet service. The average of number of food items consumed by respondents before cooking was $50.5{\pm}8.9$. The consumption of calories and nutrients was compared with the Korean Daily Recommended Dietary Allowances. The consumed calories were 60.9% of RDAs, protein 104.4%, calcium 77.1%, iron 129.8%, vitamin A 66.5%, thiamin 96.0%, riboflavin 95.7%, niacin126.6% and ascorbic acid 112.3%. This data exceeded 1/3 of the Korean Daily RDAs tremendously and tells us extreme overeating. The energy ratio of carbohydrate: fat: protein was 51.6: 29.9: 18.5. Caloric consumption of animal food was 27.9% and the consumption rate of the other nutrients from animal food was considerably high. But the consumption rate of vitamin A was 90.9% from vegetable groups. Accoding to this study, buffet service gives some advantages. It gives customers an good opportunity to vary their food intake, which enhances eating experiences and can cause an improvemont of food habits. But overeating is a problem. Therefore, we think it is necessary for those women who have influence over their family's food selection, to have nutrition education about a desirable order of eating a meal, food selection, and health problems due to overeating at buffet styled restaurant. There should be some improvement in the management of buffet service. For example, proper temperature, texture, and freshness of the food should be maintained. Prevention of mixed food smells should be considered as well. To lower the price it is desirable to reduce the number of similar items and to use seasonal food as much as possible. A buffet styled restaurant with less food items with cheaper prices is recommended. Various traditional food should be developed for the menu items. We expect buffet services to be sutable to maintain good health and to be popular to any eater.

• Journal of Intelligence and Information Systems
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• v.22 no.4
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• pp.157-176
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• 2016

For a long time, mobile phone had a sole function of communication. Recently however, abrupt innovations in technology allowed extension of the sphere in mobile phone activities. Development of technology enabled realization of almost computer-like environment even on a very small device. Such advancement yielded several forms of new high-tech devices such as smartphone and tablet PC, which quickly proliferated. Simultaneously with the diffusion of the mobile devices, mobile applications for those devices also prospered and soon became deeply penetrated in consumers' daily lives. Numerous mobile applications have been released in app stores yielding trillions of cumulative downloads. However, a big majority of the applications are disregarded from consumers. Even after the applications are purchased, they do not survive long in consumers' mobile devices and are soon abandoned. Nevertheless, it is imperative for both app developers and app-store operators to understand consumer behaviors and to develop marketing strategies aiming to make sustainable business by first increasing sales of mobile applications and by also designing surviving strategy for applications. Therefore, this research analyzes consumers' mobile application usage behavior in a frame of substitution/supplementary of application categories and several explanatory variables. Considering that consumers of mobile devices use multiple apps simultaneously, this research adopts multivariate probit models to explain mobile application usage behavior and to derive correlation between categories of applications for observing substitution/supplementary of application use. The research adopts several explanatory variables including sociodemographic data, user experiences of purchased applications that reflect future purchasing behavior of paid applications as well as consumer attitudes toward marketing efforts, variables representing consumer attitudes toward rating of the app and those representing consumer attitudes toward app-store promotion efforts (i.e., top developer badge and editor's choice badge). Results of this study can be explained in hedonic and utilitarian framework. Consumers who use hedonic applications, such as those of game and entertainment-related, are of young age with low education level. However, consumers who are old and have received higher education level prefer utilitarian application category such as life, information etc. There are disputable arguments over whether the users of SNS are hedonic or utilitarian. In our results, consumers who are younger and those with higher education level prefer using SNS category applications, which is in a middle of utilitarian and hedonic results. Also, applications that are directly related to tangible assets, such as banking, stock and mobile shopping, are only negatively related to experience of purchasing of paid app, meaning that consumers who put weights on tangible assets do not prefer buying paid application. Regarding categories, most correlations among categories are significantly positive. This is because someone who spend more time on mobile devices tends to use more applications. Game and entertainment category shows significant and positive correlation; however, there exists significantly negative correlation between game and information, as well as game and e-commerce categories of applications. Meanwhile, categories of game and SNS as well as game and finance have shown no significant correlations. This result clearly shows that mobile application usage behavior is quite clearly distinguishable - that the purpose of using mobile devices are polarized into utilitarian and hedonic purpose. This research proves several arguments that can only be explained by second-hand real data, not by survey data, and offers behavioral explanations of mobile application usage in consumers' perspectives. This research also shows substitution/supplementary patterns of consumer application usage, which then explain consumers' mobile application usage behaviors. However, this research has limitations in some points. Classification of categories itself is disputable, for classification is diverged among several studies. Therefore, there is a possibility of change in results depending on the classification. Lastly, although the data are collected in an individual application level, we reduce its observation into an individual level. Further research will be done to resolve these limitations.

• Journal of the Korean Geographical Society
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• v.30 no.2
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• pp.120-131
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• 1995

To analyze mobility patterns, this study used three Constraint (Capability Constraint, Coupling Constraint, Authority Constraint) models which were proposed in Dr. Hagerstrand's Time-space theory. This paper shows that three constraint models have some effects upon mobility by age. In this study, Capability Constraint means a certain special constraint that is what we can't do during proceeding basic natural urges like sleep, fare, etc. Coupling constraint is a physical one. Each person limits the action range for staying on a special place in special time. For instance, students have to stay in school so that they have mobility constraints. Authority Constraint is a social one. When we use urban facilities or traffic, we may be controlled by mobility sphere by an agreement or a social position. It is social agreement that the opening hour of a store, the time table of mass-transportation and a social positional control that the personal income, the standard of education. In this study it has been in a process of determination of the cluster number that degree of influences a social constraint to mobility. Considering the mobility constraint of characteristics of space divides urban and rural, people in urban area have higher mobility rate than in rural area. Resuets of determination of the cluster, show similar mobility pattern. People in urban area are connected verity of mobility which related to urban space structures with determination of cluste-number. That is to say, mobility patterns can be changed by space charactcristics. Constraints by sex and age are also social constraints and they are influenced by mobility patterns. For instance, females at the age of twenties have similar mobility pattern to the same age male but they have sudden changes after thirty's age. Male entertains a similar pattern without restriction of age. That is to say, management by sex as a social constraint affects mobility. To establish more realistic traffie policy, mobility formation should be reflected to the space in a view of social-behavioral science. To embody this, some problems should be investigated as follows. 1. As a problem of methodology, if sufficient samples ensured, we could subdivide clusters and could open up a new method of analyzing the mobility clusters by using the neuro-network. 2. Extracting actions connected with mobility and finding life cycle which is classified by daily cluste-characteristics, suitable counterproposal could be presented to the traific policy.

• Journal of Environmental Impact Assessment
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• v.27 no.1
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• pp.73-82
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• 2018

The purpose of this study is the evaluation of the impact of increase in impervious areas due to urbanization on the pollutant discharge using the HSPF model at Musim watershed. Model calibration and validation were performed based on the observed data 2015 and 2014, all simulation items have been successfully simulated such as flow, BOD, and TP. The land cover map used in the model reflected on the land use status of the Musim watershed in 2015 and the application of the development areas and locations. As a result of simulation, during rainfall daily pollutant load with the increased impervious land increased more than that before the development. However, the pollutant load decreased during the non-rainfall time. Annual pollutant load in rainfall time was significantly higher than that in non-rainfall time, BOD and TP increased. The simulation of non-point source pollutant load was applied under two assumptions, such as the increased area of impervious land and the non-change number of point source load before and after development. As the result of a simulation, the non-point source pollutant load after development was bigger than those before development. It was necessary to take measures to control non-point source pollution at the consideration status of development.

• The Korean Journal of Financial Management
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• v.27 no.1
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• pp.1-30
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• 2010

This paper tested the lead-lag relationship as well as the symmetric and asymmetric volatility spillover effects between international currency futures markets and cash markets. We use five kinds of currency spot and futures markets such as British pound, Australian and Canadian dollar, Brasilian Real and won/dollar spot and futures markets. daily closing prices covering from September 15, 2003 to July 30, 2009. For this purpose we employed dynamic time series models such as the Granger causality based on VAR and time-varying MA(1)-GJR-GARCH(1, 1)-M. The main empirical results are as follows; First, according to Granger causality test, we find that the bilateral lead-lag relationship between the five countries' currency spot and futures market. The price discover effect from currency futures markets to spot market is relatively stronger than that from currency spot to futures markets. Second, based on the time varying GARCH model, we find that there is a bilateral conditional mean spillover effects between the five currency spot and futures markets. Third, we also find that there is a bilateral asymmetric volatility spillover effects between British pound, Canadian dollar, Brasilian Real and won/dollar spot and futures market. However there is a unilateral asymmetric volatility spillover effect from Australian dollar futures to cash market, not vice versa. From these empirical results we infer that most of currency futures markets have a much better price discovery function than currency cash market and are inefficient to the information.