• Journal of Industrial Convergence
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• v.21 no.9
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• pp.41-48
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• 2023

Recently, there has been a sharp increase in the damages caused by ransomware across various sectors of society, including individuals, businesses, and nations. Ransomware is a malicious software that infiltrates user computer systems, encrypts important files, and demands a ransom in exchange for restoring access to the files. Due to its diverse and sophisticated attack techniques, ransomware is more challenging to detect than other types of malware, and its impact is significant. Therefore, there is a critical need for accurate detection and mitigation methods. To achieve precise ransomware detection, an inference engine of a detection system must possess knowledge of ransomware features. In this paper, we propose a model to extract and classify the characteristics of ransomware for accurate detection of ransomware, calculate the similarity of the extracted characteristics, reduce the dimension of the characteristics, group the reduced characteristics, and classify the characteristics of ransomware into attack tools, inflow paths, installation files, command and control, executable files, acquisition rights, circumvention techniques, collected information, leakage techniques, and state changes of the target system. The classified characteristics were applied to the existing ransomware to prove the validity of the classification, and later, if the inference engine learned using this classification technique is installed in the detection system, most of the newly emerging and variant ransomware can be detected.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.1
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• pp.27-39
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• 2024

Purpose : Smoking is a major factor in chronic obstructive pulmonary disease (COPD), but the effect of electrical cigarette smoking on COPD development is still uncertain. This study aimed to compare the functions of airways and lungs exposed to combustible cigarettes and electrical cigarettes based on the pulmonary function test (PFT) results from the Korean National Health and Nutrition Examination Survey (NHANES). Methods : This study used data from 8,942 participants with PFT results out of 47,309 total subjects from the 6th to 8th Korean NHANES (2014-2015, 2016-2018, and 2019, respectively). Individuals with diseases such as cancer, ex-smokers, and dual tobacco users were excluded. The PFT results were analyzed according to the COPD diagnostic criteria. After adjusting for confounding variables, a complex sample generalized linear model ANOVA test was performed to investigate the association between PFT results and combustible smoker or electrical cigarette user groups. Results : In an analysis based on the obstructive ventilatory disorders (forced expiratory volume in 1 second[FEV₁]/forced vital capacity[FVC]<.7), combustible cigarette smokers showed a 3.46 times higher risk of COPD compared to non-smokers, while electrical cigarette smokers exhibited no significant difference in terms of COPD-related risks compared to non-smokers. FEV₁ showed a negative relation with combustible cigarette smokers as reported elsewhere (B=-.07, p<.001). FEV₁/FVC was negatively related to both combustible cigarette smokers (B=-.03, p<.001) and electrical cigarette smokers (B=-.02, p<.001). Conclusion : FEV₁/FVC decreases were observed in the long-term exposure to both combustible and electrical cigarettes. The lower FEV₁ in the combustible cigarette group implies the worsening of the severity of COPD, suggesting more damage to the airways and lungs in the short term. Therefore, the temporary electrical cigarettes use for the transition period in order to smoking cessation potentially aids to reduce the harmful effect of combustible cigarettes in COPD development.

• Information Systems Review
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• v.22 no.1
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• pp.147-165
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• 2020

The sharing economy service is now spreading in various fields such as accommodation, cars and bicycles. In particular, bicycle-sharing service have become very popular around the world, and since September 2015, Seoul has been providing a bicycle-sharing service called 'Ttareungi'. However, the number of bicycles is unbalanced among rental stations continuously according to the user's bicycle use. In order to solve these problems, we employed social network analysis using Ttareungi data in Seoul, Korea. We analyzed degree centrality, closeness centrality, betweenness centrality and k-core. As a result, the degree centrality was found to be closely linked with bus or subway transfer center. Closeness centrality was found to be in an unbalanced departure and arrival frequency or poor public transport proximity. Betweenness centrality means where the frequency of departure and arrival occurs frequently. Finally, the k-core analysis showed that Mapo-gu was the most important group by time zone. Therefore, the results of this study may contribute to the planning of relocation and additional installation of bike rental station in Seoul.

• Phonetics and Speech Sciences
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• v.16 no.2
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• pp.59-69
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• 2024

Due to differences in singing styles and voice production between classical and popular music singers, their knowledge and practice regarding vocal hygiene may differ. This study compared the knowledge and practice of vocal hygiene among 121 university undergraduate students (58 classical and 63 popular music vocal majors). Additionally, the correlation between the level of knowledge and practice of vocal hygiene and the subjective voice evaluation was examined. The results revealed that both knowledge and practice of vocal hygiene were significantly higher in classical than popular music vocal majors, and that vocal hygiene practice was significantly higher than knowledge in the entire group. In addition, there was a weak positive correlation between knowledge and practice of vocal hygiene; and a weak negative correlation between vocal hygiene practice and subjective voice evaluation. This study suggests that popular music vocal majors have relatively lower levels of knowledge and practice in vocal hygiene than classical music vocal majors. It also highlights the need to provide tailored vocal hygiene education programs for both classical and popular music vocal majors, as they show low levels of knowledge and practice in certain aspects of vocal hygiene.

• The Journal of Bigdata
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• v.8 no.2
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• pp.1-13
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• 2023

Current analysis of air passengers mainly relies on statistical methods, but there are limitations in analyzing detailed aspects such as travel routes, number of regional passengers and airport access times. However, with the advancement of big data technology and revised three data acts, big data-based transportation analysis has become more active. Mobile communication data, which can precisely track the location of mobile phone terminals, can serve as valuable analytical data for transportation analysis. In this paper, we propose a air passenger Origin/Destination (O/D) extraction algorithm based on mobile communication data that overcomes the limitations of existing air transportation user analysis methods. The algorithm involves setting airport signal detection zones at each airport and extracting air passenger based on their base station connection history within these zones. By analyzing the base station connection data along the passenger's origin-destination paths, we estimate the entire travel route. For this paper, we extracted O/D information for both domestic and international air passengers at all domestic airports from January 2019 to December 2020. To compensate for errors caused by mobile communication service provider market shares, we applied a adjustment to correct the travel volume at a nationwide citizen level. Furthermore correlation analysis was performed on O/D data and aviation statistics data for air traffic users based on mobile communication data to verify the extracted data. Through this, there is a difference in the total amount (4.1 for domestic and 4.6 for international), but the correlation is high at 0.99, which is judged to be useful. The proposed algorithm in this paper enables a comprehensive and detailed analysis of air transportation users' travel behavior, regional/age group ratios, and can be utilized in various fields such as formulating airport-related policies and conducting regional market analysis.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.249-259
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• 2008

The purpose of this study was to analyze the users' behaviors and to suggest development strategies in Uljin Kumgang pine tree(Pinus densiflora for. erecta) eco-forest(UKPEF), which is located in Kyeongbuk. The data were collected by interviewing 122 visitors to september 3 from august 29, 2007 with a constructed questionnaire. The results of the analysis are as follows. 1. The major visitors of UKPEF are male and the age between 20 to 30, the residents of the Uljin county with relatively high academic background. 2. The motive of visiting UKPEF is mainly by the beauty and taste of Kumgang pine tree and the condition of the forest. The visitors are mainly composed of family, not big group. 3. The visitors of UKPEF have obtained information about the Kumgang fine tree forest mainly from friends, not from the internet or travel agency. 4. The visitors of UKPEF pointed out lack of convenient facilities such as toilets and water-supply facilities. However, visitors are satisfied by the condition of the forest. 5. The visitors of UKPEF set a high value on Kumgang fine tree, So, more active marketing strategy about Uljin Kumgang pine tree has to be established. 6. The visitors of UKPEF are more satisfied by the Uljin Kumgang pine tree forest than expected. The development strategies of UKPEF are suggest as follows. (1) Auto tram system has to be set up and new trail should be constructed to attract more visitors and people of other regions. (2) To attract group tourists, new program should be developed. (3) Advertisement through internet or travel agency has to be developed. (4) Government(local) should make a plan to register the forest as World natural heritage. (5) Monitoring and evaluation system has to be developed to satisfy tourists. In conclusion, the efforts of taking care of and preserving the UKPEF should be made at the national level. I hope that more Koreans can have chance to feel and experience the value and excellence ofthe Uljin Kumgang pine tree(Pinus densiflora for. erecta)

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.104-113
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• 2012

This study aimed to find out the improvement plan through analyzing the perception of the expert group engaged in landscape architectural construction and to focus on analyzing the expert groups' experience on Landscape Construction Defects (LCD), defect liability, warranty period, and implementation of the defect liability. The results are as follows: 1. Regarding the experience on the LCD, landscape construction contractors were an awareness of the LCD issue at a serious level, while public-sector clients recognize moderately the LCD issue; and on the first priority in defect implementation, landscape construction contractors considered repair cost while public-sector clients value the identifying causes of defects. 2. In disagreement on the defect liability, landscape construction contractors attributed it to client's lack of responsibility for maintenance while public-sector clients ascribed it to the absence of dealing a criteria with LCD, and regarding the appropriate defect implementation, public-sector clients preferred the following objective by dealing the criteria with LCD while landscape construction contractors advocates by sharing the responsibilities for dealing with LCD based on the identified causes of construction defects. 3. Regarding the warranty period, the public-sector clients considered the 2-year warranty period as appropriate while landscape construction contractors considered it comparatively long, and concerning the commencement of defect warranty period, the public-sector clients viewed it as it should commence to cover the overall completion of the construction while landscape construction contractors perceived it to start on the completion of each work. 4. As for the improvement of the defect implementation system, public-sector clients considered it necessary to establish the objective dealing the criteria with LCD while landscape construction contractors viewed the legislation of maintenance duty. Also, with regard to the important value in establishing and dealing the criteria with LCD, public-sector clients pointed out the objective of the criteria for determining the defects per work type while landscape construction contractors suggested client (user)'s maintenance duty. Because of research, because the system in dealing with LCD is an absence of LCD management agency and dealing the criteria with LCD, it is needed to establish an LCD management agency and make the system in dealing with LCD.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.1-14
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• 2008

According to technology acceptance model(TAN) which is one of the most important research models for explaining IT users' behavior, on intention of using IT is determined by usefulness and ease of use of it. However, TAM wouldn't explain the performance of using IT while it has been considered as a very good model for prediction of the intention. Many people would not be confirmed in the performance of using IT until they can control it at their will, although they think it useful and easy to use. In other words, in addition to usefulness and ease of use as in TAM, controllability is also should be a factor to determine acceptance of IT. Especially, there is a very close relationship between controllability and ease of use, both of which explain the other sides of control over the performance of using IT, so called perceived behavioral control(PBC) in social psychology. The objective of this study is to identify the relationship between ease of use and controllability, and analyse the effects of both two beliefs over performance and intention in using IT. For this purpose, we review the issues related with PBC in information systems studies as well as social psychology, Based on a review of PBC, we suggest a research model which includes the relationship between control and performance in using IT, and prove its validity empirically. Since it was introduced as qa variable for explaining volitional control for actions in theory of planned behavior(TPB), there have been confusion about concept of PBC in spite of its important role in predicting so many kinds of actions. Some studies define PBC as self-efficacy that means actor's perception of difficulty or ease of actions, while others as controllability. However, this confusion dose not imply conceptual contradiction but a double-faced feature of PBC since the performance of actions is related with both self-efficacy and controllability. In other words, these two concepts are discriminated and correlated with each other. Therefore, PBC should be considered as a composite concept consisting of self-efficacy and controllability, Use of IT has been also one of important areas for predictions by PBC. Most of them have been studied by analysis of comparison in prediction power between TAM and TPB or modification of TAM by inclusion of PBC as another belief as like usefulness and ease of use. Interestingly, unlike the other applications in social psychology, it is hard to find such confusion in the concept of PBC in the studies for use of IT. In most of studies, controllability is adapted as PBC since the concept of self-efficacy is included in ease of use explicitly. Based on these discussions, we can suggest perceived use control(PUC) which is defined as perception of control over the performance of using IT and composed of controllability and ease of use as sub-concepts. We suggest a research model explaining acceptance of IT which includes the relationships of PUC with attitude and performance of using IT. For empirical test of our research model, two user groups are selected for surveying questionnaires. In the first group, there are freshmen who take a basic course for Microsoft Excel, and the second group consists of senior students who take a course for analysis of management information by Excel. Most of measurements are adapted ones that have been validated in the other studies, while performance is real score of mid-term in each class. In result, four hypotheses related with PUC are supported statistically with very low significance level. Main contribution of this study is suggestion of PUC through theoretical review of PBC. Specifically, a hierarchical model of PUC are derived from very rigorous studies in the relationship between self-efficacy and controllability with a view of PBC in social psychology. The relationship between PUC and performance is another main contribution.

• Asia Marketing Journal
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• v.11 no.4
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• pp.95-119
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• 2010

Although there have been many studies regarding the inconsistency between consumers' attitudes and behavior, prior research has almost exclusively focused on the relationship between the attitude before behavior and the initial behavior. Relatively little research has been conducted on consumer satisfaction after purchase and post-purchase behavior. This research proposed that the relationship between satisfaction and post-purchase behavior is moderated by consumers' psychological characteristics such as need for cognitive closure(NCC) and temporal self-construal(SC). The need for cognitive closure refers to individuals' desire for a firm answer to a question and an aversion toward ambiguity. We assumed the need for cognitive closure as a major moderating variable because it is judged that the requirement for cognition clearly varies between when a consumer repurchases the same product and seeks a new alternative. Individuals who tend to end cognition due to time constraints or inappropriate conditions may display considerable cognitive impatience or impulsivity and has a higher probability in repurchasing the same product than a consumer without such limitations. They would avoid further consideration for new alternatives and the likelihood of the repurchase for prior alternative would increase. As hypothesized, significant moderating effect of the NCC was confirmed. This result gives a significant implication for a corporate to establish effective marketing strategies. For a corporate or product brand that has been occupying the market after entering the market earlier, it would be effective to maintain need for cognitive closure high in the existing consumers and thereby preventing the consumers from being interested in the new alternatives. On the other hand, new brands that have just entered the market need to lower the potential consumers' need for cognitive closure so that the consumers can be interested in new alternatives. Along with need for cognitive closure, temporal self-construal also turned out to moderate the satisfaction-repurchase. temporal SC reflects the extent to which individuals view themselves either as an individuated entity or in relation to others. Consumers under a temporarily independent SC would repurchase former alternative again according to their prior satisfaction and evaluation. In contrast, consumers in temporal interdependent SC tended to switch to a new alternative because they value interpersonal relationships above anything else and have a tendency to rely heavily on in-group opinions. When they are confronted with additional opinions, it is highly probable that he/she will choose a new product as an alternative. By proving the impact that temporal self-construal has on repurchasing behavior, this study is providing the marketers with new standards for establishing successful promotional strategies. For example, if the buyer and the user is the same for a product, it would be effective for the seller to convince the consumer to make decision subjectively by encouraging temporal independent self-construal. On the contrary, in the case where the purchase is made by an individual but the product is consumed by a group of people. For example, a housewife is more likely to choose the products or brands that her husband or children prefer rather than the ones that she likes by herself. In that case, emphasizing how the whole family can be satisfied and happy about the product would be effective for promoting repurchase.

• Journal of Environmental Health Sciences
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• v.17 no.2
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• pp.54-66
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• 1991

As a result of measuring illumination and making up a question at home visit directly by investigator who trained over twenty days period from October 4 to 24, 1990, in order to render help which illumination problem against house, society against eyes or framing of health instruction potgram by seizing natural lighting actual conditions of house and actual conditions of wearing spectacles and by investigating interrelationship, I can summarize as follows. 1) In property of investigation subject, woman 66.9%, In an age, the twenties was largest of 27.4%, the forties was 20.2%, the fifties was 18.6%, the thirties was 17.4%. In academic career, those of upper secondary school grauates was largest of 28.6%, those who possess university career was 25.9%, those who middle school career was 20.9%, decoding of Korean alphabet was 2%. 2) By a residence area, a big city was 43.3%, farming and fishing villages were 20.3%, the rest was a small town and the administrative office of town, township. In positon of house, the middle area was 43.6%, resident of suburb area was 38.0%. In form of house, a Korean-style house was 40.8%, a western-style house was 34.8%, an apartment house was 11.0%. In the a standard of living, the middle classes 77.2%, the lower classes were 15.3%. In residential house unit of area, from 21 to 30 unit of area was largest of 31.5%, from 10 to 20 unit of area was 19.9%, from 31 to 40 was 18.7%. 3) The wearing spectacles rate of study user was 44.1%. By the area, those who wearing spectacles was more than a half of 50.8% in the resident of big city area. As passing from the farm area to the city, that is being resident of big city was high wearing spectacles rate. In position of house, as being residence in central street showed high wearing spectacles rate. (central street was 51.5%, the middle area was 44.5% and the suburb area was 40.1%.) It seemed similarity difference a variable by position of house from wearing spectacles in standard of 1%. By form of house, wearing spectacles rate those who resident in apartment house was 49.5%, that rate those who resident in a western-style house was high of 49.0%, that rate those who resident in a Korean-style house was the lowest 39.0%. By social position of resident in room, in students case who study showed very high, as university students were very high of 62.3% idn wearing spectacles rate, middle and high school students 'were 50.0%, members of society were 47.6%, workers 20.3%. It seemed similarity difference from academic career in standard of 1%. By an age, the thirties was high of 54.1% in wearing spectacles rate, the twenties was 43.2%, the teenage was the lowest of 11.8%. 4) In illumination of study, over 200Lux was high of 40.1%. but below 99Lux which inappropriate illumination to see the books was 32.4%. Average by area, below 99Lux was 22.7% and over 400Lux was 50.0% in case of wooden floor. As examine by area, below 99Lux was high of 27.0% a case of wooden floor in the big city area, it was not good in illumination passing from the farm area(15.0%) to the city(19.0%). Average illlumination by area of the main living room below 99Lux was high of 37.5%, less than 200Lux was 58.5% of whole. In general, illumination of the main livingroom was inappropriate. By area, the big city was 32.5% below 99Lux, the middle and small city area were 33.8%, town and township area were 45.0%, farming and fishing area were 42.8%. By area, in the big city, illumination of study was 52.5% over 200Lux and 28.9% below 99Lux. In case of the middle and small city, study user of below 99Lux was 38.8% and over 200Lux was 46.9%. In case of the seat of town township, below 99Lux was 34.1% and over 200Lux was 39.7%. In case of farming and fishing area, illumination of study was 33.4% below 99Lux and 48.4% over 200Lux. It tends to high rate of inappropriate illumination. 5) By position of house, in case of wooden floor, less than 100Lux was 24.5% in central street. It was bad illumination than others position of house. In case of the main livingroom, less than 100Lux was 40.4% in the suburb area. It was bad iliumnation than others position of house. In case of study, less than 100Lux was 35.4% in the middle area, it was worse in illumination. In case of the main living room, is seemed similarity difference in standard of 1%. 6) By form of house, in case of wooden floor, illumination of less than 100Lux was 23.8% in a western-style house, it was bad illumination than others form of house. In case of the main livingroom, illumination of less than 100Lux was 47.4% in a Korean-style house, it was remarkably bad illumination than others form of house. In case of study, a Korean-style house was 38.8%, it was very bad illumination than others form of house. In case of the main livingroom and study, it seemed similatrity difference each as P < 0.01 and P < 0.05 in standard of 1%. 7) The wearing spectacles rate of those who use room of illumination over 400Lux was 40.7%, and that of those who use room of illumination less than 100Lux was 28.1%. It seemed similarity differecce in standard of 1%. 8) In period of wearing spectacles, 21.3% of total investigator-highest-was from before five years, 8.6% was from before three years. Among those who use of illumintion less than 99Lux, 34.0% began to wear spectacles from before two years 31.7% was from before five years, 30.3% was from before four years. It seemed similarity difference from period of wearing spectacles by illumination in standard of 1 %. 9) Among cause which sight grow worse, the first was that it was each 33.2% and 27.4% in response rate because watch TV nearly to wearing spectacles person and non-wearing person. The second was that a lot of seeing books was 25.3% in wearing spectacles person and response rate for dark illumination was 7.4% in nonwearing spectacles person. It seemed similarity difference in standard of 1%. (P < 0.01). 10) In experience which take medicine good for eyes, it was 50.1% in wearing spectacles person and 8.5% in non-wearing spectacles person. It seemed similarity difference in standard of 1%(P < 0.01). As we have seen above, inappropriate illumination can be a cause of wearing spectacles. Nevertheless, actually, is realities to indifferent against illumination of house. So it must learn knowledge about health obstacle of illumination through society instruction and school eduction against students as well as general residents. In case that natural lighting is inappropriate structural of house, we must be able to maintain appropriate illumination through artificial illumination. And so eyes which is core of human life have to be protected, related the authorities, related group, and all health medical personnel will organically cooperate with and make efforts.