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Microbiological Evaluation of Foods and Kitchen Environments in Childcare Center and Kindergarten Foodservice Operations (보육시설과 유치원 급식의 식품 및 환경 미생물의 오염도 평가)

  • Seol, Hye-Rin;Park, Hyoung-Su;Park, Ki-Hwan;Park, Ae-Kyung;Ryu, Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.2
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    • pp.252-260
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    • 2009
  • Whereas the numbers of childcare centers and kindergartens are increasing rapidly, systematic management to control the food safety of foodservice operation is not yet well established. Samples from 12 centers in Seoul and Gyeonggi Province were collected to assess the microbiological quality of 32 raw materials, 24 cooked foods, 76 food-contact surfaces (knives, cutting boards, dish towels and gloves), 17 employees' hands and 12 air-borne bacteria. The microbiological analyses were performed for aerobic plate counts (APC), Enterobacteriaceae, E. coli and 7 pathogens (B. cereus, C. jejuni, C. perfringens, L. monocytogenes, Salmonella spp., S. aureus, and V. parahaemolyticus). Among raw materials, E. coli ($1.39{\sim}2.08\;\log\;CFU/g$) were detected in 4 out of 6 meats and 7.46 log CFU/g of APC in tofu. High enterobacteriaceae levels of 4.23, 5.14 and 4.19 log CFU/g were found in cucumber salad, steamed spinach with seasonings and steamed bean sprout with seasonings, respectively. No pathogens were found in all samples except for C. perfringens detected from raw spinach and raw lotus root. Only APC and enterobacteriaceae were found in food-contact surfaces. Two of the 23 knives and three of the 24 kitchen boards showed over 500 CFU/$100\;cm^2$ of APC; also, APC levels (5.03 to 5.44 log CFU/g) were detected in 4 of the 12 dish towels. Only one glove showed Enterobacteriaceae (2.44 log CFU/glove) contamination. Enterobacteriaceae were found in 2 employees' hands ($2.37{\sim}4.44\;\log\;CFU$/hand) among the 16 employees. The contamination levels of air-borne bacteria were shown unacceptable in two (2.25 and 2.30 log CFU/petri-film/15 min) out of the 12 kitchen areas. These results suggest that the microbiological hazards in some foods and environments are not well controlled and thus a guideline should be provided to ensure the food safety in childcare center and kindergarten foodservice operations.

A Survey on the Hearing Disturbance of High School Students in Korea (한국고교생(韓國高校生)에 대(對)한 난청실태조사(難聽實態調査))

  • Rhee, Kyu-Shik;Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • v.5 no.1
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    • pp.115-123
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    • 1972
  • As a link of chain study program of school health, a survey was made up by the screening test with audiometry for hearing disturbance on 18,675 high school students who are mainly aged in 15-19 years from November 5.1969 to October 30. 1970. The results obtained were summerized as follows. According to our criteria as table 3, the rates of the profound, the severe and the moderate who required the appropriate hearing aids were 0.02%, 0.03% and 0.14% respectively:-the cumulative percentage was 0.197. When the marginal, 0.23% should be included the cumulative rate was 0.41%. But there was no-significance by sex and school classes. If we will make the special classes for them one class would be estimated out of 10,000 persons when a class is formed with about 15 persons. Otherwise when we examined that according to each ear of persons, the rates of the profound, the severe and the moderate were 0.17%, 0.22% and 0.33% respectively and their cumulative percentage wag 0.72. There was no significance also by sex and age. By the way, the rate of hearing disturbance in urban high school students tended to lower than rural. And the perceptive disturbance was higher than rural in rate. The conductive disturbance tended to oppose in comparison with the above.

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The Effects of Intravenous Methylprednisolone Pulse Therapy by Mendoza Protocol in Primary and Secondary Nephrotic Syndrome (일차성 및 이차성 신증후군에서 Mendoza Protocol에 의한 Intravenous Methylprednisolone Pulse Therapy의 효과)

  • Lee Kyoung-Jae;Han Jae-Hyuk;Lee Young-Mock;Kim Ji-Hong;Kim Pyung-Kil
    • Childhood Kidney Diseases
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    • v.5 no.2
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    • pp.117-124
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    • 2001
  • Purpose : Since Mendoza(1990)'s report that long term methylprednisolone pulse therapy by Mendoza protocol (MP therapy) is a good treatment option in focal segmental glomerulosclerosis(FSGS), there have been reports of the effects of this therapy in steroid-resistant nephrotic syndrome. However, no studies have been performed on the effects of MP therapy in steroid- dependent nephrotic syndrome and secondary nephrotic syndrome. In this study, we investigated the effects of long term MP therapy in primary and secondary nephrotic syndrome in which previous treatment options were not effective. Methods : We chose 10 children who were diagnosed with steroid-dependent minimal change nephrotic syndrome(SD-MCNS), who had shown frequent relapse during the immunocompromised or cytotoxic therapy Period, and 6 children with FSGS and 5 children with secondary nephrotic syndrome children, who had shown no response during the previous therapy period. We treated these patients according to Mendoza protocol involving infusions of high doses of methylprednisolone, often in combination with oral cyclophosphamide for 82 weeks. Results : In all the 10 children with SD-MCNS, complete remission was visible on average of $18{\pm}9$ days after MP therapy was started. However, all these children relapsed during or after MP therapy. In these children, the mean relapse rate prior to MP therapy was $2.1{\pm}1.0$ relpases/year, which was reduced to $1.4{\pm}0.9$ relapses/year during MP therapy(P>0.05) and rose to $2.7{\pm}1.0$ relapse/year after MP therapy. Of the 6 children with FSGS, 4 children($67\%$) showed complete remission, of whom 3 children($50\%$) remained in the remission status during the follow up period, $1.2{\pm}0.7$ years, after the end of MP therapy. 2 children($33\%$) showed no response. All of the 5 children with secondary nephrotic syndrome showed remission and remained in the remissiom status during the follow up period, $1.7{\pm}0.6$ years The only side effect of MP therapy was transient hypertension in 10 children of ail subjects during the intravenous infusion of methylprednisolone. Conclusion : We conclude that although long term MP therapy is not effective in the treatment of SD-MCNS, it is an effective therapy against intractable FSGS and secondary nephrotic syndrome. (J Korean Soc Pediatr Nephrol 2001 ; 5 : 117-24)

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Taxonomical Classification and Genesis of Jeju Series in Jeju Island (제주도 토양인 제주통의 분류 및 생성)

  • Song, Kwan-Cheol;Hyun, Byung-Geun;Moon, Kyung-Hwan;Jeon, Seung-Jong;Lim, Han-Cheol;Lee, Shin-Chan
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.2
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    • pp.230-236
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    • 2010
  • Jeju Island is a volanic island which is located about 96 km south of Korean Peninsula. Volcanic ejecta, and volcaniclastic materials are widespread as soil parent materials throughout the island. Soils on the island have the characteristics of typical volcanic ash soils. This study was conducted to reclassify Jeju series based on the second edition of Soil Taxonomy and to discuss the formation of Jeju series in Jeju Island. Morphological properties of typifying pedon of Jeju series were investigated, and physico-chemical properties were analyzed according to Soil survey laboratory methods manual. The typifying pedon has dark brown (10YR 3/3) silt clay loam A horizon (0~22 cm), strong brown (7.5YR 4/6) silty clay BAt horizon (22~43 cm), brown (7.5YR 4/4) silty clay Bt1 horizon (43~80 cm), brown (7.5YR 4/6) silty clay loamBt2 horizon (80~105 cm), and brown (10YR 5/4) silty clay loam Bt3 horizon (105~150 cm). It is developed in elevated lava plain, and are derived from basalt, and pyroclastic materials. The typifying pedon contains 1.3~2.1% oxalate extractable (Al + 1/2 Fe), less than 85%phosphate retention, and higher bulk density than 0.90 Mg $m^{-3}$. That can not be classified as Andisol. But it has an argillic horizon from a depth of 22 to 150 cm, and a base saturation (sum of cations) of less than 35% at 125 cm below the upper boundary of the argillic horizon. That can be classified as Ultisol, not as Andisol. Its has 0.9% or more organic carbon in the upper 15 cm of the argillic horizon, and can be classified as Humult. It dose not have fragipan, kandic horizon, sombric horizon, plinthite, etc. in the given depths, and key out as Haplohumult. A hoizon (0~22 cm) has a fine-earth fraction with both a bulk density of 1.0 Mg $cm^{-3}$ or less, and Al plus 1/2 Fe percentages (by ammonium oxalate) totaling more than 1.0. Thus, it keys out as Andic Haplohumult. It has 35% or more clay at the particle-size control section, and has thermic soil temperature regime. Jeju series can be classified as fine, mixed, themic family of Andic Haplohumults, not as ashy, thermic family of Typic Hapludands. In the western, and northern coastal areas which have a relatively dry climate in Jeju Island, non Andisols are widely distributed. Mean annual precipitation increase 110 mm, and mean annual temperature decrease $0.8^{\circ}C$ with increasing elevation of 100m. In the western, and northern mid-mountaineous areas Andisols, and non Andisols are distributed simultaneously. Jeju series distributed mainly in the western and northern mid-mountaineous areas are developed as Ultisols with Andic subgroup.

The Comparative Study of on Pump CABG during Pulsatile $(T-PLS^{TM})$ and Nonpulsatile $(Bio-pump^{TM})$ Perfusion (관상동맥우회술 시 사용된 박동성펌프$(T-PLS^{TM})$와 비박동성펌프$(Bio-pump^{TM})$의 비교연구)

  • Park Young-Woo;Her Keun;Lim Jae-Ung;Shin Hwa-Kyun;Won Yong-Soon
    • Journal of Chest Surgery
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    • v.39 no.5 s.262
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    • pp.354-358
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    • 2006
  • Background: Pulsatile pumps for extracorporeal circulation have been known to be better for tissue perfusion than non-pulsatile pumps but be detrimental to blood corpuscles. This study is intended to examine the risks and benefits of $T-PLS^{TM}$ through the comparison of clinical effects of $T-PLS^{TM}$ (pulsatile pump) and $Bio-pump^{TM}$ (non-pulsatile pump) used for coronary bypass surgery. Material and Method: The comparison was made on 40 patients who had coronary bypass using $T-PLS^{TM}\;and\;Bio-pump^{TM}$ (20 patients for each) from April 2003 to June 2005. All of the surgeries were operated on pump beating coronary artery bypass graft using cardiopulmonary extra-corporeal circulation. Risk factors before surgery and the condition during surgery and the results were compared. Result: There was no significant difference in age, gender ratio, and risk factors before surgery such as history of diabetes, hypertension, smoking, obstructive pulmonary disease, coronary infarction, and renal failure between the two groups. Surgery duration, hours of heart-lung machine operation, used shunt and grafted coronary branch were little different between the two groups. The two groups had a similar level of systolic arterial pressure, diastolic arterial pressure and mean arterial pressure, but pulse pressure was measured higher in the group with $T-PLS^{TM}\;(46{\pm}15\;mmHg\;in\;T-PLS^{TM}\;vs\;35{\pm}13\;mmHg\;in\;Bio-pump^{TM},\;p<0.05)$. The $T-PLS^{TM}$-operated patients tended to produce more urine volume during surgery, but the difference was not statistically significant $(9.7{\pm}3.9\;cc/min\;in\;T-PLS^{TM}\;vs\;8.9{\pm}3.6\;cc/min\;in\;Bio-pump^{TM},\;p=0.20)$. There was no significant difference in mean duration of respirator usage and 24-hour blood loss after surgery between the two groups. Plasma free Hb was measured lower in the group with $T-PLS^{TM}\;(24.5{\pm}21.7\;mg/dL\;in\;T-PLS^{TM}\;versus\;46.8{\pm}23.0mg/dL\;in\;Bio-pump^{TM},\;p<0.05)$. There was no significant difference in coronary infarction, arrhythmia, renal failure and morbidity rate of cerebrovascular disease. There was a case of death after surgery (death rate of 5%) in the group tested with $T-PLS^{TM}$, but the death rate was not statistically significant. Conclusion: Coronary bypass was operated with $T-PLS^{TM}$ (Pulsatile flow pump) using a heart-lung machine. There was no unexpected event caused by mechanical error during surgery, and the clinical process of the surgery was the same as the surgery for which $Bio-pump^{TM}$ was used. In addition, $T-PLS^{TM}$ used surgery was found to be less detrimental to blood corpuscles than the pulsatile flow has been known to be. Authors of this study could confirm the safety of $T-PLS^{TM}$.

Effect of Temperature During Grain Filling Stage on Grain Quality and Taste of Cooked Rice in Mid-late Maturing Rice Varieties (등숙기 온도변이가 중만생종 벼의 쌀 품질과 식미치에 미치는 영향)

  • Choi, Kyung-Jin;Park, Tae-Shik;Lee, Choon-Ki;Kim, Jung-Tae;Kim, Jun-Hwan;Ha, Ki-Yong;Yang, Woon-Ho;Lee, Chung-Keun;Kwak, Kang-Su;Park, Hong-Kyu;Nam, Jeong-Kwon;Kim, Jeong-Il;Han, Gwi-Jung;Cho, Yong-Sik;Park, Young-Hee;Han, Sang-Wook;Kim, Jae-Rok;Lee, Sang-Young;Choi, Hyun-Gu;Cho, Seung-Hyun;Park, Heung-Gyu;Ahn, Duok-Jong;Joung, Wan-Kyu;Han, Sang-Ik;Kim, Sang-Yeol;Jang, Ki-Chang;Oh, Seong-Hwan;Seo, Woo-Duck;Ra, Ji-Eun;Kim, Jun-Young;Kang, Hang-Won
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.4
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    • pp.404-412
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    • 2011
  • This experiment was conducted to clarify the effect of the temperature for grain filling duration on quality and taste of cooked rice cultivated in different region in Korea. In 2006 and 2007, 4 mid-late maturing group of rice varieties (Nampyeongbyeo, Ilpumbyeo, Junambyeo and Dongjin 1) were cultivated in 28 experimental plots of 27 different regions located in 8 provinces. The taste of cooked rice were positively correlated with 1,000 grain weight but negatively correlated with protein content of brown rice. Mean temperature for 30 days from heading was more closely correlated with grain filling and tastes of cooked rice than those for 40 days. Though, the optimum mean temperature for the best taste of cooked rice for 30 days after heading was 22.1 to $23.1^{\circ}C$ depending on varieties, in general, 1,000 grain weight and cooked rice taste were the highest in the mean temperature of $22.2^{\circ}C$ for 30 days from heading. But grains were poorly ripened in case of the mean temperature lower than $21.0^{\circ}C$ for 30 days after heading. Therefore, for the better taste of cooked rice in Korea, the developing new rice varieties and cultivation method should be focused to adjust the mean temperature within $22-23^{\circ}C$ during the period of 30 days after heading.

The Prevalence of Obesity and Underweight in Adolescents in Incheon Area and the Relationship between Serum Cholesterol Level and Obesity (인천지역 청소년의 비만도와 혈청 콜레스테롤치와의 관계)

  • Kim, Myung Hyun;Kim, Tae Wan;Hong, Young Jin;Son, Byong Kwan;Pai, Soo Hwan;Chang, Kyung Ja;Kim, Soon Ki
    • Clinical and Experimental Pediatrics
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    • v.45 no.2
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    • pp.174-182
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    • 2002
  • Purpose : The purpose of this study was to investigate the prevalence of obese and underweight adolescents in Incheon area and to examine the relationship between serum cholesterol level and obesity, then to assess the nutritional condition of adolescents. Methods : With a questionnaire regarding their demographic characteristics, blood samples were obtained from apparently healthy students aged 12 to 24 years by venipuncture at April and May, 2000. We measured the obesity index using standard body weight and the body mass index(BMI) according to the criteria established by the Korean Pediatric Society in 1998. Obesity was defined as BMI more than 95 percentile, and underweight less than 15 percentile by age and sex. Results : A total of 1,456 students(M : F=685 : 771) aged 12 to 24 years were included in this study. The prevalence of obesity by standard body weight in adolescents in Incheon were 11.7% : mild obesity 6.5%, moderate 4.6%, and severe 0.5%. By BMI, the prevalence of obesity was 6.4% in males and 6.2% in females. In males, the prevalence of obesity in rural areas was 8.5%, lower than in urban areas(14.3%). The prevalence of underweight by obesity index was 34.1% in rural areas and 22.9% in urban areas. In females, the prevalence of obesity was 12.5% in rural areas and 19.6% in urban areas. There were no significant differences between the two regions(P=0.529). The prevalence of obesity increased with age till 16.3% of peak prevalence in 16 years of age, and then decreased. In males, the prevalence of obesity in academic and vocational school were 13.7% and 9.7%, respectively(P=0.116). In females of the academic and vocational school, the prevalence of obesity was 6.8% and 18.0%, respectively(P=0.001). In obese adolescents, serum total cholesterol was over 200 mg/dL in 6.2%. Conclusion : This study revealed that the prevalence of obesity in adolescents was about 12% and that the prevalence of underweight adolescents was considerably high. We think nutritional assessment and intervention are warranted for adolescent students.

Determinants of Consumer Responses to Retail Out-of-Stocks (점포내 품절상황에서 소비자 반응행동유형별 결정요인)

  • Chun, Dal-Young;Choi, Jong-Rae;Joo, Young-Jin
    • Journal of Distribution Research
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    • v.16 no.4
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    • pp.29-64
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    • 2011
  • Overview of Research: Product availability is one of important competences of store to fulfill consumer needs. If stock-outs which means a product what consumer wants to buy is not available occurs, consumer will face decision-making uncertainty that leads to consumer's negative responses such as consumer dissatisfaction on store. Stockouts was much studied in the field of academia as well as practice in other countries. However, stock-outs has not been researched at all in Marketing and/or Distribution area in Korea. The main objectives of this study are to find out determinants of consumer responses such as Substitute, Delay, and Leave(SDL) when consumer encounters out-of-stock situation and then to examine the effects of these factors on consumer responses. Specifically, this study focuses on situational characteristics(e.g., purchase urgency and surprise), store characteristics (e.g., product assortment and store convenience), and consumer characteristics (e.g., brand loyalty and store loyalty). Then, this study empirically investigates relationships these factors with consumers behaviors such as product substitution, purchase delay, and store switching.

    shows the research model of this study. To accomplish above-mentioned research objectives, the following ten hypotheses were proposed and verified : ${\bullet}$ H 1 : When out-of-stock situation occurs, purchase urgency will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 2 When out-of-stock situation occurs, surprise will decrease product substitution and purchase delay but will Increase store switching among consumer responses. ${\bullet}$ H 3 : When out-of-stock situation occurs, purchase quantities will increase product substitution and store switching but will decrease purchase delay among consumer responses. ${\bullet}$ H 4 : When out-of-stock situation occurs, pre-purchase plan will decrease product substitution but will increase purchase delay and store switching among consumer responses. ${\bullet}$ H 5 : When out-of-stock situation occurs, product assortment will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 6 : When out-of-stock situation occurs, competitive store price image will increase product substitution and purchase delay but will decrease store switching among consumer responses. ${\bullet}$ H 7 : When out-of-stock situation occurs, store convenience will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 8 : When out-of-stock situation occurs, salesperson services will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 9 : When out-of-stock situation occurs, brand loyalty will decrease product substitution but will increase purchase delay and store switching among consumer responses. ${\bullet}$ H 10 When out-of-stock situation occurs, store loyalty will increase product substitution and purchase delay but will decrease store switching among consumer responses. Analysis: Data were collected from 353 respondents who experienced out-of-stock situations in various store types such as large discount stores, supermarkets, etc. Research model and hypotheses were verified using multinomial logit(MNL) analysis. Results and Implications: is the estimation results of l\1NL model, and
    shows the marginal effects for each determinant to consumer's responses(SDL). Significant statistical results were as follows. Purchase urgency, purchase quantities, pre-purchase plan, product assortment, store price image, brand loyalty, and store loyalty were turned out to be significant determinants to influence consumer alternative behaviors in case of out-of-stock situation. Specifically, first, product substitution behavior was triggered by purchase urgency, surprise, purchase quantities, pre-purchase plan, product assortment, store price image, brand loyalty, and store loyalty. Second, purchase delay behavior was led by purchase urgency, purchase quantities, and brand loyalty. Third, store switching behavior was influenced by purchase urgency, purchase quantities, pre-purchase plan, product assortment, store price image, brand loyalty, and store loyalty. Finally, when out-of-stock situation occurs, store convenience and salesperson service did not have significant effects on consumer alternative responses.

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  • A Study of 'Emotion Trigger' by Text Mining Techniques (텍스트 마이닝을 이용한 감정 유발 요인 'Emotion Trigger'에 관한 연구)

    • An, Juyoung;Bae, Junghwan;Han, Namgi;Song, Min
      • Journal of Intelligence and Information Systems
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      • v.21 no.2
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      • pp.69-92
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      • 2015
    • The explosion of social media data has led to apply text-mining techniques to analyze big social media data in a more rigorous manner. Even if social media text analysis algorithms were improved, previous approaches to social media text analysis have some limitations. In the field of sentiment analysis of social media written in Korean, there are two typical approaches. One is the linguistic approach using machine learning, which is the most common approach. Some studies have been conducted by adding grammatical factors to feature sets for training classification model. The other approach adopts the semantic analysis method to sentiment analysis, but this approach is mainly applied to English texts. To overcome these limitations, this study applies the Word2Vec algorithm which is an extension of the neural network algorithms to deal with more extensive semantic features that were underestimated in existing sentiment analysis. The result from adopting the Word2Vec algorithm is compared to the result from co-occurrence analysis to identify the difference between two approaches. The results show that the distribution related word extracted by Word2Vec algorithm in that the words represent some emotion about the keyword used are three times more than extracted by co-occurrence analysis. The reason of the difference between two results comes from Word2Vec's semantic features vectorization. Therefore, it is possible to say that Word2Vec algorithm is able to catch the hidden related words which have not been found in traditional analysis. In addition, Part Of Speech (POS) tagging for Korean is used to detect adjective as "emotional word" in Korean. In addition, the emotion words extracted from the text are converted into word vector by the Word2Vec algorithm to find related words. Among these related words, noun words are selected because each word of them would have causal relationship with "emotional word" in the sentence. The process of extracting these trigger factor of emotional word is named "Emotion Trigger" in this study. As a case study, the datasets used in the study are collected by searching using three keywords: professor, prosecutor, and doctor in that these keywords contain rich public emotion and opinion. Advanced data collecting was conducted to select secondary keywords for data gathering. The secondary keywords for each keyword used to gather the data to be used in actual analysis are followed: Professor (sexual assault, misappropriation of research money, recruitment irregularities, polifessor), Doctor (Shin hae-chul sky hospital, drinking and plastic surgery, rebate) Prosecutor (lewd behavior, sponsor). The size of the text data is about to 100,000(Professor: 25720, Doctor: 35110, Prosecutor: 43225) and the data are gathered from news, blog, and twitter to reflect various level of public emotion into text data analysis. As a visualization method, Gephi (http://gephi.github.io) was used and every program used in text processing and analysis are java coding. The contributions of this study are as follows: First, different approaches for sentiment analysis are integrated to overcome the limitations of existing approaches. Secondly, finding Emotion Trigger can detect the hidden connections to public emotion which existing method cannot detect. Finally, the approach used in this study could be generalized regardless of types of text data. The limitation of this study is that it is hard to say the word extracted by Emotion Trigger processing has significantly causal relationship with emotional word in a sentence. The future study will be conducted to clarify the causal relationship between emotional words and the words extracted by Emotion Trigger by comparing with the relationships manually tagged. Furthermore, the text data used in Emotion Trigger are twitter, so the data have a number of distinct features which we did not deal with in this study. These features will be considered in further study.

    Improved Social Network Analysis Method in SNS (SNS에서의 개선된 소셜 네트워크 분석 방법)

    • Sohn, Jong-Soo;Cho, Soo-Whan;Kwon, Kyung-Lag;Chung, In-Jeong
      • Journal of Intelligence and Information Systems
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      • v.18 no.4
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      • pp.117-127
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      • 2012
    • Due to the recent expansion of the Web 2.0 -based services, along with the widespread of smartphones, online social network services are being popularized among users. Online social network services are the online community services which enable users to communicate each other, share information and expand human relationships. In the social network services, each relation between users is represented by a graph consisting of nodes and links. As the users of online social network services are increasing rapidly, the SNS are actively utilized in enterprise marketing, analysis of social phenomenon and so on. Social Network Analysis (SNA) is the systematic way to analyze social relationships among the members of the social network using the network theory. In general social network theory consists of nodes and arcs, and it is often depicted in a social network diagram. In a social network diagram, nodes represent individual actors within the network and arcs represent relationships between the nodes. With SNA, we can measure relationships among the people such as degree of intimacy, intensity of connection and classification of the groups. Ever since Social Networking Services (SNS) have drawn increasing attention from millions of users, numerous researches have made to analyze their user relationships and messages. There are typical representative SNA methods: degree centrality, betweenness centrality and closeness centrality. In the degree of centrality analysis, the shortest path between nodes is not considered. However, it is used as a crucial factor in betweenness centrality, closeness centrality and other SNA methods. In previous researches in SNA, the computation time was not too expensive since the size of social network was small. Unfortunately, most SNA methods require significant time to process relevant data, and it makes difficult to apply the ever increasing SNS data in social network studies. For instance, if the number of nodes in online social network is n, the maximum number of link in social network is n(n-1)/2. It means that it is too expensive to analyze the social network, for example, if the number of nodes is 10,000 the number of links is 49,995,000. Therefore, we propose a heuristic-based method for finding the shortest path among users in the SNS user graph. Through the shortest path finding method, we will show how efficient our proposed approach may be by conducting betweenness centrality analysis and closeness centrality analysis, both of which are widely used in social network studies. Moreover, we devised an enhanced method with addition of best-first-search method and preprocessing step for the reduction of computation time and rapid search of the shortest paths in a huge size of online social network. Best-first-search method finds the shortest path heuristically, which generalizes human experiences. As large number of links is shared by only a few nodes in online social networks, most nods have relatively few connections. As a result, a node with multiple connections functions as a hub node. When searching for a particular node, looking for users with numerous links instead of searching all users indiscriminately has a better chance of finding the desired node more quickly. In this paper, we employ the degree of user node vn as heuristic evaluation function in a graph G = (N, E), where N is a set of vertices, and E is a set of links between two different nodes. As the heuristic evaluation function is used, the worst case could happen when the target node is situated in the bottom of skewed tree. In order to remove such a target node, the preprocessing step is conducted. Next, we find the shortest path between two nodes in social network efficiently and then analyze the social network. For the verification of the proposed method, we crawled 160,000 people from online and then constructed social network. Then we compared with previous methods, which are best-first-search and breath-first-search, in time for searching and analyzing. The suggested method takes 240 seconds to search nodes where breath-first-search based method takes 1,781 seconds (7.4 times faster). Moreover, for social network analysis, the suggested method is 6.8 times and 1.8 times faster than betweenness centrality analysis and closeness centrality analysis, respectively. The proposed method in this paper shows the possibility to analyze a large size of social network with the better performance in time. As a result, our method would improve the efficiency of social network analysis, making it particularly useful in studying social trends or phenomena.


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