• Title/Summary/Keyword: Time Study

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MICROLEAKAGE OF THE EXPERIMENTAL COMPOSITE RESIN WITH THREE COMPONENT PHOTOINITIATOR SYSTEMS (3종 광중합개시제를 함유한 실험용 복합레진의 미세누출도)

  • Kim, Ji-Hoon;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.34 no.4
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    • pp.333-339
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    • 2009
  • This study was done to determine if there is any difference in microleakage between experimental composite resins, in which various proportions of three component photoinitiators (Camphoroquinone, OPPI, Amine) were included. Four kinds of experimental composite resin were made by mixing 3.2% silanated barium glass (78 wt.%, average size; 1 ${\mu}m$) with each monomer system including variously proportioned photoinitiator systems used for photoinitiating BisGMA/BisEMA/TEGDMA monomer blend (37.5:37.5:25 wt.%). The weight percentage of each component were as follows (in sequence Camphoroquinone, OPPI, Amine): Group A - 0.5%, 0%, 1% / Group B - 2%, 0.2%, 2% / Group C - 0.2%, 1%, 0.2% / Group D - 1%, 1%, 2%. Each composite resin was used as a filling material for round class V cavities (diameter: 2/3 of mesiodistal width; depth: 1.5 mm) made on extracted human premolars and they were polymerized using curing light unit (XL 2500, 3M ESPE) for 40 s with an intensity of 600 mW/$cm^2$. Teeth were thermocycled fivehundred times between $50^{\circ}C$and $550^{\circ}C$for 30s at each temperature. Electrical conductivity (${\mu}A$) was recorded two times (just after thermocycling and after three-month storage in saline solution) by electrochemical method. Microleakage scores of each group according to evaluation time were as follows [Group: at first record / at second record; unit (${\mu}A$)]: A: 3.80 (0.69) / 13.22 (4.48), B: 3.42 (1.33) / 18.84 (5.53), C: 4.18 (2.55) / 28.08 (7.75), D: 4.12 (1.86) / 7.41 (3.41). Just after thermocycling, there was no difference in microleakage between groups, however, group C showed the largest score after three-month storage. Although there seems to be no difference in microleakage between groups just after thermocycling, composite resin with highly concentrated initiation system or classical design (Camphoroquinone and Amine system) would be more desirable for minimizing microleakage after three-month storage.

Aspects and Significance of Musa basjoo, a Landscaping Plant - Focused on Analysis of Old Paintings of Chosun Dynasty - (조경식물 파초(Musa basjoo) 식재 양상과 그 의미 - 조선시대 옛 그림 분석을 중심으로 -)

  • Rho, Jae-Hyun;Kim, Young-Suk;Goh, Yeo-Bin
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.2
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    • pp.23-36
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    • 2010
  • The purpose of this study is to infer the aspects and significance of Musa basjoo of latter part of Chosun Dynasty by analyzing the planting tendency and planting location of Musa basjoos drawn in total 77 old paintings and the characteristics of the paintings where Musa basjoos appeared, while trying to understand symbolic meanings of floral languages as well as the images and significance of Musa basjoos which appeared in the prose and poetry of Chosun Dynasty, and the results are as follows; With its floral languages of 'waiting', 'parting' and 'beauty', Musa basjoo represented the wealth and resuscitation and it aroused the elegance of hermits in its Taoistic sense. And it also represented 'the unworldliness to get out of transient human affairs' in its Buddhistic sense. Musa basjoos which appeared in 'Garden Custom Painting(庭園雅集圖)', 'Gosa Figure Painting(故事人物圖)' and 'Gyehoe Painting(契會圖)' is considered a device to increase the unworldly atmosphere of gardens and to dignify the elegant meetings of scholars, reflected by the high appearance frequencies of cranes and deer. And it seems that the meaning of Musa basjoo in certain paintings like 'Life-time Paintings(平生圖)', 'Castle City Painting(盛市圖), and 'Cultivating and Weaving Painting(耕織圖)' is an aspiration for wealth and prosperity, and the Musa basjoos planted in temples are considered to have symbolic meanings of aspiration for 'Salvation through Belief' as well as a unworldly meaning which reminds the transiency of human affairs. In addition, the expected effect of experiencing 'the sound of rain falling on the leaves of Musa basjoo' has been pursued, which can be confirmed by the fact that Firmiana simlex with wide leaves similar to Musa basjoo can be frequently spotted near the houses. Meanwhile, Musa basjoos seem to have been planted mainly in front garden or side garden around detached house and Musa basjoos inside the houses seem to have been planted mainly in right side when viewed from the entrance, in relation with the location of bedrooms where it is easier to hear the sounds from the right side of the environment. And the paintings where Musa basjoos appear with strange rocks and bizarre stones among other things have greater part of all the paintings, which is considered a kind of intentional landscaping and a product of mixed materials for elegant appreciation. And the major characters of the painting were involved in the activities of scholars such as arts, and the activities of minor characters were greatly related to their everyday lives. Musa basjoo of Chosun Dynasty in $17^{th}$ and $18^{th}$ century was one of the symbols necessary for description of gardens. And it provided the images of rainy scenes together with scholar culture which had a meaning of self-discipline, and it is assumed that the planting of Musa basjoo with the spirit of cease lessen deavor of a new leaf pushing up the tree and the spirit of resuscitation had the same trace of wheels in the city space of our country as the decline of scholar culture of Chosun Dynasty.

Analysis of factors affecting customer satisfaction of HACCP applied restaurant in highway service area (HACCP 적용 고속도로 휴게소 식당의 고객 만족도에 영향을 주는 요인 분석)

  • Kim, Tae-Hyeong;Bae, Hyun-Joo
    • Journal of Nutrition and Health
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    • v.50 no.3
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    • pp.294-301
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    • 2017
  • Purpose: The purposes of this study were to investigate food consumption practices and analyze factors that influence customer satisfaction of an HACCP applied restaurant in a highway service area. Methods: A total of 207 customer responses were used for data analysis. Statistical analyses were conducted using the SPSS program (ver. 22.0) for $x^2$-test, Pearson correlation analysis, and multiple regression analysis. Results: Reasons for visiting the highway area were using the restroom (86.0%), purchasing of meals or snacks (70.1%), taking a rest (58.5%), and shopping (3.4%) and selection attributes of food sold in the highway service area were food taste (48.8%), food safety (33.3%), and waiting time for meal (10.7%). According to the results of the survey, udon (66.2%) was the most preferred meal, followed by instant noodles (56.0%), kimbap (50.7%), pork cutlet (38.2%), and bibimbap (29.0%). In addition, coffee (73.4%) was the most preferred among snacks and beverages, followed by beverages (58.9%), walnut cake (53.1%), mineral water (52.2%), and hotbar (52.2%). Satisfaction evaluation scores of foods sold in the highway service area were highest for appropriate portion size, followed by food safety, menu variety, food taste, and reasonable price. Overall customer satisfaction scores regarding the restaurant in the highway service area was 3.24 out of 5 points on average. According to the results of the multiple regressing analysis, food taste (p < 0.001) and reasonable price (p < 0.01) had significant positive effects on overall customer satisfaction. Conclusion: To enhance customer satisfaction, restaurant managers in the highway service area should implement HACCP, improve food taste, and set up a proper price for food sold at the restaurant in the highway service area.

Analysis of comparisons of eating-out, dietary lifestyles, and healthy dietary competencies among middle-aged consumers according to obesity status and gender for implications of consumer education (소비자교육을 위한 중년기 소비자의 성별, 비만도별 외식 행동, 식생활 라이프스타일 및 건강한 식생활역량의 차이 분석)

  • Park, Jong Ok
    • Journal of Nutrition and Health
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    • v.51 no.1
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    • pp.60-72
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    • 2018
  • Purpose: The purpose of this study was to determine differences in eating-out, dietary life styles, and healthy dietary competencies among middle-aged consumers according to obesity status and gender for implications of consumer education. Methods: Data were drawn from the 2016 Food Consumption Behavior Survey, and 3,022 subjects (mail 1,388; female 1,634) who were middle-aged adults were investigated. Analysis of variance with $Scheff\acute{e}$ test, t-test, $x^2$-test, and factor analysis were performed using SPSS v.24. Results: Males showed less interest in diet than females. For both males and females, higher BMI degrees were associated with higher levels of interest in diet. For frequency, monthly average consumption expenditure, one-time cost for eating out, and drinking frequency, males showed higher levels than females. Especially for the male group, higher obesity status was associated with higher levels of eating out and drinking. Dietary lifestyles of males and females turned out to be very similar. For the male group, normal weight group was more likely to show 'health and high quality pursuit dietary life-style' than the other groups. For females, the normal weight group were more likely to show 'health and high quality pursuit dietary life-style' and 'safety pursuit dietary life-style' than the other groups. The level of 'healthy dietary competence' for females was found to be higher than that for males. For the female group, there were significant differences according to obesity status, and practice was more important than knowledge in determining a healthy dietary life. Conclusion: For dietary life-related education for obese middle-aged consumers, it is important to emphasize less eating-out and drinking and less overeating while eating-out based on the results that eating-out, drinking, and overeating in the obesity group were significantly higher than in the normal group. It is important to focus on the value of dietary life and diverse foods, based on the results that the obesity group was less likely to be have healthy dietary lifestyles and consume less diverse foods than the normal group.

Lipid Oxidation in Dried Shellfish during the Storage (패류 건제품의 저장 중 지질산화)

  • CHO Ho-Sung;CHO Tae-Yong;LEE Kang-Ho;LEE Nahm-Gull;JOO Dong-Sik;KIM Gyeong-Eup;LEE Jong-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.4
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    • pp.594-598
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    • 1998
  • In this study oxidative deterioration of dried sea mussel and baby clam stored at $4{\pm}2^{\circ}C$ and $25{\pm}2^{\circ}C$ were investigated. Acid value of samples were higher at $25^{\circ}C$ than those at $4^{\circ}C$ throughout the storage period. And it was higher in dried baby clam than in sea mussel regardless of storage temperatures. Peroxide value of dried sea mussel and baby clam stored at $25^{\circ}C$ tended to decrease after 30 and 60 days, respectively. Thiobarbituric acid and carbonyl value of samples stored at $4^{\circ}C$ were higher than those stored at $25^{\circ}C$ throughout the storage period. In case of sea mussel, However they were lower stored at $4^{\circ}C$ than at $25^{\circ}C$ in 30 days. Amino nitrogen increased until 60 days and then decreased in all samples. Fluorescence intensity associated with interaction between carbonyl compound and amino compound was increased with storage temperature and time but it decreased slowly after 60 days.

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Arthroscopic Repair of Traumatic Subscapularis Tendon Tear (외상성 견갑하건 파열의 관절경하 봉합술)

  • Cho, Su-Hyun;Cho, Hyung-Lae;Ku, Jung-Hoei;Hwang, Tae-Hyok;Park, Man-Jun;Choi, Jae-Hyuk
    • Journal of the Korean Arthroscopy Society
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    • v.14 no.3
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    • pp.180-187
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    • 2010
  • Purpose: Rotator cuff tears involving the subscapularis are less common than those involving the superior and posterior rotator cuff. The purpose of the present study was to report the clinical results of repair of isolated traumatic tears of the subscapularis tendon. Materials and Methods: Fifteen patients (13 males, 2 females; mean age 46.2 years; range 35 to 52) with unilateral ruptures of the subscapularis tendon after trauma who underwent arthroscopic repair between February 2003 and October 2008 were reviewed retrospectively. All the cases were isolated tears of the subscapularis without the involvement of any other rotator cuff tendon and were followed for at least two years (mean 28 months). The entire subscapularis was involved in 9 cases and the tear was localized to the upper two thirds in 6 cases. The preoperative and postoperative status of patients with isolated subscapularis tears were analyzed using the Constant Score, American Shoulder and Elbow Society Index (ASES Index) and postoperative integrity was determined through magnetic resonance imaging. Results: The average clinical outcome scores and strength were all improved significantly at the time of the final follow-up. The constant shoulder score improved from 41.5 to 81.3 points (P<0.05) compared to before surgery and ASES index improved from 46.4 to 89.6 points (P<0.05) postoperatively. Thirteen patients (87%) were satisfied with the result of the treatment. The total tears were significantly more improved by surgery than the partial tears. In 12 of 15 patients (80%) were judged to reveal healed tendon on magnetic resonance imaging at a mean of 13 months postoperatively. The postoperative score was significantly lower for the patients with a failed repair than it was for those with an intact repair (P<0.05). Conclusion: Repair of traumatic isolated subscapularis tears through arthroscopic techniques effectively restores patient function with regard to pain, mobility, strength and postoperative tendon integrity. The postoperative integrity of the repair correlates with the functional results and the total tears were more improved by surgery than the partial tears, but future studies may be needed.

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Bankruptcy Prediction Modeling Using Qualitative Information Based on Big Data Analytics (빅데이터 기반의 정성 정보를 활용한 부도 예측 모형 구축)

  • Jo, Nam-ok;Shin, Kyung-shik
    • Journal of Intelligence and Information Systems
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    • v.22 no.2
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    • pp.33-56
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    • 2016
  • Many researchers have focused on developing bankruptcy prediction models using modeling techniques, such as statistical methods including multiple discriminant analysis (MDA) and logit analysis or artificial intelligence techniques containing artificial neural networks (ANN), decision trees, and support vector machines (SVM), to secure enhanced performance. Most of the bankruptcy prediction models in academic studies have used financial ratios as main input variables. The bankruptcy of firms is associated with firm's financial states and the external economic situation. However, the inclusion of qualitative information, such as the economic atmosphere, has not been actively discussed despite the fact that exploiting only financial ratios has some drawbacks. Accounting information, such as financial ratios, is based on past data, and it is usually determined one year before bankruptcy. Thus, a time lag exists between the point of closing financial statements and the point of credit evaluation. In addition, financial ratios do not contain environmental factors, such as external economic situations. Therefore, using only financial ratios may be insufficient in constructing a bankruptcy prediction model, because they essentially reflect past corporate internal accounting information while neglecting recent information. Thus, qualitative information must be added to the conventional bankruptcy prediction model to supplement accounting information. Due to the lack of an analytic mechanism for obtaining and processing qualitative information from various information sources, previous studies have only used qualitative information. However, recently, big data analytics, such as text mining techniques, have been drawing much attention in academia and industry, with an increasing amount of unstructured text data available on the web. A few previous studies have sought to adopt big data analytics in business prediction modeling. Nevertheless, the use of qualitative information on the web for business prediction modeling is still deemed to be in the primary stage, restricted to limited applications, such as stock prediction and movie revenue prediction applications. Thus, it is necessary to apply big data analytics techniques, such as text mining, to various business prediction problems, including credit risk evaluation. Analytic methods are required for processing qualitative information represented in unstructured text form due to the complexity of managing and processing unstructured text data. This study proposes a bankruptcy prediction model for Korean small- and medium-sized construction firms using both quantitative information, such as financial ratios, and qualitative information acquired from economic news articles. The performance of the proposed method depends on how well information types are transformed from qualitative into quantitative information that is suitable for incorporating into the bankruptcy prediction model. We employ big data analytics techniques, especially text mining, as a mechanism for processing qualitative information. The sentiment index is provided at the industry level by extracting from a large amount of text data to quantify the external economic atmosphere represented in the media. The proposed method involves keyword-based sentiment analysis using a domain-specific sentiment lexicon to extract sentiment from economic news articles. The generated sentiment lexicon is designed to represent sentiment for the construction business by considering the relationship between the occurring term and the actual situation with respect to the economic condition of the industry rather than the inherent semantics of the term. The experimental results proved that incorporating qualitative information based on big data analytics into the traditional bankruptcy prediction model based on accounting information is effective for enhancing the predictive performance. The sentiment variable extracted from economic news articles had an impact on corporate bankruptcy. In particular, a negative sentiment variable improved the accuracy of corporate bankruptcy prediction because the corporate bankruptcy of construction firms is sensitive to poor economic conditions. The bankruptcy prediction model using qualitative information based on big data analytics contributes to the field, in that it reflects not only relatively recent information but also environmental factors, such as external economic conditions.

The Need for Paradigm Shift in Semantic Similarity and Semantic Relatedness : From Cognitive Semantics Perspective (의미간의 유사도 연구의 패러다임 변화의 필요성-인지 의미론적 관점에서의 고찰)

  • Choi, Youngseok;Park, Jinsoo
    • Journal of Intelligence and Information Systems
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    • v.19 no.1
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    • pp.111-123
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    • 2013
  • Semantic similarity/relatedness measure between two concepts plays an important role in research on system integration and database integration. Moreover, current research on keyword recommendation or tag clustering strongly depends on this kind of semantic measure. For this reason, many researchers in various fields including computer science and computational linguistics have tried to improve methods to calculating semantic similarity/relatedness measure. This study of similarity between concepts is meant to discover how a computational process can model the action of a human to determine the relationship between two concepts. Most research on calculating semantic similarity usually uses ready-made reference knowledge such as semantic network and dictionary to measure concept similarity. The topological method is used to calculated relatedness or similarity between concepts based on various forms of a semantic network including a hierarchical taxonomy. This approach assumes that the semantic network reflects the human knowledge well. The nodes in a network represent concepts, and way to measure the conceptual similarity between two nodes are also regarded as ways to determine the conceptual similarity of two words(i.e,. two nodes in a network). Topological method can be categorized as node-based or edge-based, which are also called the information content approach and the conceptual distance approach, respectively. The node-based approach is used to calculate similarity between concepts based on how much information the two concepts share in terms of a semantic network or taxonomy while edge-based approach estimates the distance between the nodes that correspond to the concepts being compared. Both of two approaches have assumed that the semantic network is static. That means topological approach has not considered the change of semantic relation between concepts in semantic network. However, as information communication technologies make advantage in sharing knowledge among people, semantic relation between concepts in semantic network may change. To explain the change in semantic relation, we adopt the cognitive semantics. The basic assumption of cognitive semantics is that humans judge the semantic relation based on their cognition and understanding of concepts. This cognition and understanding is called 'World Knowledge.' World knowledge can be categorized as personal knowledge and cultural knowledge. Personal knowledge means the knowledge from personal experience. Everyone can have different Personal Knowledge of same concept. Cultural Knowledge is the knowledge shared by people who are living in the same culture or using the same language. People in the same culture have common understanding of specific concepts. Cultural knowledge can be the starting point of discussion about the change of semantic relation. If the culture shared by people changes for some reasons, the human's cultural knowledge may also change. Today's society and culture are changing at a past face, and the change of cultural knowledge is not negligible issues in the research on semantic relationship between concepts. In this paper, we propose the future directions of research on semantic similarity. In other words, we discuss that how the research on semantic similarity can reflect the change of semantic relation caused by the change of cultural knowledge. We suggest three direction of future research on semantic similarity. First, the research should include the versioning and update methodology for semantic network. Second, semantic network which is dynamically generated can be used for the calculation of semantic similarity between concepts. If the researcher can develop the methodology to extract the semantic network from given knowledge base in real time, this approach can solve many problems related to the change of semantic relation. Third, the statistical approach based on corpus analysis can be an alternative for the method using semantic network. We believe that these proposed research direction can be the milestone of the research on semantic relation.

Cytotoxicity and Antigenotoxic Effects of Cordyceps militaris Extracts (번데기동충하조(Cordyceps militaris) 추출물의 세포독성 및 유전독성 억제효과)

  • 김미남;최승필;이득식;함승시
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.5
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    • pp.921-927
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    • 2001
  • This study was performed to investigated the effects on the cytotoxicity and antigenotoxicity of Cordyceps militaris extracts on the human cancer cell lines. The ethanol extract and five fractions which were hexane, chloroform, ethylacetate, butanol and aqueous were screened for crytotoxicity on human lung carcinoma(A549). human breast adenocarcinoma (MCF-7) human epitheloid carcinoma(HeLa), human fibrosarcoma(HT1080) human hepatocellular carcinoma(Hep3B), human gastric carcinoma(KATOIII) and chronic myelogenous leukemia(K562) cell by SRB and MTT assays. The results showed that growth inhibition rates of the human cancer cell in the presence of Cordyceps militaris were inhibited with increasing concentration of the extract. The ethanol extract from Cordyceps militaris had strong inhibitory effects in1 mg/mL treatment by SRB assay , showing 89.4%, 85.7%, 72.9% and 65.5% inhibition in HT1080, HeLa, Hep3B and A549, respectively. The treatment of 1 mg/mL hexane fraction by SRB assay had the strongest cytotoxicity with 97.0% on HT1080 followed by MCF-7(92.9%) and HeLA(90.3%). The inhibition ration on KATOIII by MTT assay was much higher in the butanol (83.7%) and aqueous (80.4%) than in the ethanol extract (61.5%) And also, K562 showed similar tendency with KATOIII. The effects of Cordyceps militaris extracts on the frequencies of micronucleated polychromatic erythrocytes (MNPCEs) induced by N-methyl-N-nitro-N-nitrosoguanidime(MNNG) were investigated in the bone-marrow cells of ICR male mice. The amount of 10, 20, 40 and 80 mg/kg of each extract were administered to animals immediately after injection of MNNG, and the exposure time was 36 hours. Significant reductions(p<0.05) with 39.7%, 52.7%, 71.4% and 83.9% were observed in the frequencies of MNPCE when 10, 20, 40 and 80 mg/kg of the hexane fraction of Coryceps militarus extracts were given to the mice.

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Consumer's Perception and Utilization of Food Labels by Age and Gender (일반 소비자의 연령과 성별에 따른 식품표시에 대한 인식 및 활용도)

  • Jung, Hyun-Young;Kim, Hyun-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.3
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    • pp.437-444
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    • 2016
  • This study was carried out to investigate food label perception and utilization classified by age and sex. Questionnaires were collected from 938 male and female customers aged in their 20's to 50's from February 4th to March 30th 2014. Regarding checking food labels at the time of purchase, 73.8% of consumers checked food labels, and there was a significant difference by age and sex. Female more often checked food labels than males, and the 40's group showed a higher ratio of checking food labels than other age groups. The main reason for checking food label was 'confirming expiration date' (60%), 'ingredients' (16.4%), and 'nutrition contents' (13.7%). The main reason not checking food labels was 'too small and insufficient to understand' (50.3%), 'too difficult to understand' (16.4%), and 'have no concern' (14.9%). There was a significant difference by age, as in the 50's group showed a higher ratio of 'too small and insufficient to understand' than the other age groups, and 20's and 30's groups showed a higher ratio of 'too difficult to understand'. The overall satisfaction score was 2.96, awareness score was 2.88, and reliability score was 2.93. A total of 96% answered that food labelling education is needed. Therefore, food labelling education for consumers is required to encourage consumers to purchase healthy foods.