• Title/Summary/Keyword: Difference in Differences

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Suicide Ideation and the Related Factors among Korean Adults by Gender (한국 성인의 성별 자살생각 관련 요인 분석)

  • Park, Eunok
    • Journal of agricultural medicine and community health
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    • v.39 no.3
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    • pp.161-175
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    • 2014
  • Objectives: This study investigates the prevalence of suicide ideation and its the related factors by gender among Korean adults. Methods: National cross-sectional data from the database of the first and second year of $5^{th}$ Korean National Health and Nutritional Examination Survey (KNHANES V-1, V-2) were used for this study. 13,165 adults (${\geq}20$ years) were included in this analysis. Results: The prevalence of suicide ideation was 9.8% for men, 18.9% for women. Renal failure, depression, melancholy, stress, perceived health status, and smoking were significant risk factors among both men and women for suicide ideation. Divorced, separated or widowed of marital status and severe physical activity were related factors of suicide ideation for men. Low educational attainment, and alcohol dependency were associated factors of suicide ideation for women. Conclusions: There was gender difference of prevalence and risk factors of suicide ideation. These gender differences should be considered for planning and implementing suicide prevention program.

Meat Quality Characteristics of Korean Native Ducks according to Stocking Density (사육밀도에 따른 토종오리 고기의 육질 특성)

  • Hong, Eui-Chul;Kang, Bo-Seok;Kang, Hwan-Ku;Jeon, Jin-Joo;Kim, Hyun-Soo;Son, Jiseon;Kim, Chan-Ho
    • Korean Journal of Poultry Science
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    • v.47 no.2
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    • pp.61-68
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    • 2020
  • This study was conducted to compare and analyze meat quality of Korean native duck (KND) meat relative to stocking density. The stocking densities under investigation were 4, 5, 6, 7, 8 and 9 birds/㎡. The experiment comprised six treatments and four replications, wherein the breast meat (pH, meat color, and physicochemical properties) and leg meat (fatty acid contents) of 8-week-old KNDs (2.8±0.2 kg) were used. pH of breast meat decreased linearly and quadratically (P<0.05) as stocking density increased. Ash content also decreased linearly (P<0.05) as stocking density increased; however, moisture, fat, and protein contents did not differ significantly among treatments. Furthermore, meat color and cooking loss (CL) increased linearly (P<0.05) as stocking density increased whereas neither shear force (SF) nor water holding capacity (WHC) displayed a significant difference among treatments. Palmitic acid (C16:0) and stearic acid (C18:0) contents decreased quadratically (P<0.05) as stocking density increased whereas, conversely, linoleic acid (C18:1n9) and eicosenoic acid (C20:1n9) contents increased linearly (P<0.05) as stocking density increased. Additionally, γ-linoleic acid (C18:3n6) content increased linearly and quadratically (P<0.05) as stocking density increased, but a decrease (P<0.05) was observed in arachidonic acid (C20:4n6) content. Saturated fatty acid (SFA) and total unsaturated fatty acid (TUFA) contents did not show significant differences among treatments relative to stocking density. However, monounsaturated fatty acid (MUFA) content increased linearly (P<0.05) and polyunsaturated fatty acid (PUFA) content decreased linearly (P<0.05) as stocking density increased. These results can be utilized as basic data for research on the effect of stocking density on KNDs.

The Influence of Accommodation on Watching Home 3D TV at Close Distance (가정용 3D TV의 근거리 시청이 조절기능에 미치는 영향)

  • Kim, Jung-Ho;Hwang, Hae-Young;Kang, Ji-Hun;Yu, Dong-Sik;Kim, Jae-Do;Son, Jeong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.2
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    • pp.157-163
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    • 2013
  • Purpose: This study was investigated weather watching 2D and 3D images effecting on accommodative function (AF), and differences between changes of AF by 2D and 3D. Methods: 50 subjects (male 30, female 20) aged 20's to 40's years old ($22.9{\pm}3.93$ years) who are available to watching 3D images were participated for this study. Accommodative amplitude (AA) by near point of accommodation (NPA), accommodative response (AR), positive and negative relative accommodation (PRA, NRA), accommodative facility (AF) were measured before, after watching 2D and 3D images at 1 m distance for 30 minutes respectively. Results: Accommodative amplitude after both watching 2D and 3D images decreased comparing to before watching images, and AA after watching 3D images was significantly lower than after watching 2D images. AR after both watching 2D and 3D images increased comparing to before watching images, but there was no difference between 2D and 3D. PRA and NRA were not significantly different between before, after watching 2D and 3D images. Accommodation speed by AF was increased for before watching ($13.52{\pm}3.32$ cpm) following by for after watching 2D images ($14.28{\pm}3.21$ cpm) and for watching 3D images ($14.90{\pm}3.27$ cpm). Conclusions: Watching images at close distance is effect to accommodation functions, and sequence of AA decrease of before watching images following by after watching 2D images and after watching 3D images may effect to asthenopia with same sequence as AA decrease. The results of increase of AF after watching images, specially 3D images show a possibility of vision therapy and further detail VT studies using 3D images are required in the future.

Quality Change during Harvest Time and Storage of Various Cabbages Grown on High Land by Different Transplanting Times (정식시기에 따른 고랭지 양배추의 수확 및 저장중 품질변화)

  • Eum, Hyang-Lan;Lee, Young-Hoon;Hong, Sae-Jin;Shin, Il-Sheob;Yeoung, Young-Rok
    • Journal of Bio-Environment Control
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    • v.21 no.2
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    • pp.95-101
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    • 2012
  • This study was conducted to investigate the effect of climate conditions during cultivation and harvesting on the quality and storability of fresh bulb cabbage (Brassica oleracea L. var. capitata). Plug seedlings of six cabbage cultivars were transplanted to Gangneung-Wonju University high elevation research station in Gangwon province (780 m above sea level, lat. $37.5^{\circ}N$.) and harvested with four different harvest times like August 3 ($1^{st}$), August 13 ($2^{nd}$), August 23 ($3^{rd}$), and September 10 ($4^{th}$), respectively from 50 days after transplanting. Weight loss, Hunter color factors, firmness, and soluble solids content (SSC) of the cabbage bulbs were investigated during storage at $3^{\circ}C$ (85% RH) and $25^{\circ}C$ (60% RH). Decreased bulb weight and poor quality cabbages were apparent at the late transplanting (July 14) and harvest (September 10) respectively. Quality index such as firmness and SSC at August 23 ($3^{rd}$) harvested cabbage was better than August 3 ($1^{st}$) and August 13 ($2^{nd}$) cabbages due to the good weather condition just before harvesting. The cv. 'Speed king' and 'Minix 40' showed good qualities among the cultivars, especially when the bulbs were harvested during sunny day conditions from one week before harvesting. Also SSC was influenced by weather condition before harvesting rather than transplanting date, while firmness was influenced by transplanting and harvest date. However, the differences among the cultivars were not significant. The potential of storage as maintaining the quality was different, depending on weather conditions at harvest time. Generally the storage periods of six cultivars were around 3~5 days and 9~10 days at room and low temperature, respectively. However, the August 3 ($1^{st}$) harvested cabbage lost their marketable quality very fast because of rainy and cloudy weather condition before harvesting and also storability of bulbs was 2 days and 4 days at room temperature and $3^{\circ}C$, respectively. Quality index was also not significant difference among cultivars.

Functional Brain Mapping Using $H_2^{15}O$ Positron Emission Tomography ( I ): Statistical Parametric Mapping Method ($H_2^{15}O$ 양전자단층촬영술을 이용한 뇌기능 지도 작성(I): 통계적 파라메터 지도작성법)

  • Lee, Dong-Soo;Lee, Jae-Sung;Kim, Kyeong-Min;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.3
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    • pp.225-237
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    • 1998
  • Purpose: We investigated the statistical methods to compose the functional brain map of human working memory and the principal factors that have an effect on the methods for localization. Materials and Methods: Repeated PET scans with successive four tasks, which consist of one control and three different activation tasks, were performed on six right-handed normal volunteers for 2 minutes after bolus injections of 925 MBq $H_2^{15}O$ at the intervals of 30 minutes. Image data were analyzed using SPM96 (Statistical Parametric Mapping) implemented with Matlab (Mathworks Inc., U.S.A.). Images from the same subject were spatially registered and were normalized using linear and nonlinear transformation methods. Significant difference between control and each activation state was estimated at every voxel based on the general linear model. Differences of global counts were removed using analysis of covariance (ANCOVA) with global activity as covariate. Using the mean and variance for each condition which was adjusted using ANCOVA, t-statistics was performed on every voxel To interpret the results more easily, t-values were transformed to the standard Gaussian distribution (Z-score). Results: All the subjects carried out the activation and control tests successfully. Average rate of correct answers was 95%. The numbers of activated blobs were 4 for verbal memory I, 9 for verbal memory II, 9 for visual memory, and 6 for conjunctive activation of these three tasks. The verbal working memory activates predominantly left-sided structures, and the visual memory activates the right hemisphere. Conclusion: We conclude that rCBF PET imaging and statistical parametric mapping method were useful in the localization of the brain regions for verbal and visual working memory.

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Effect of resin cement color on the color of commercially available zirconia crown (레진시멘트 색상이 상용 지르코니아 크라운의 색상에 미치는 영향)

  • Ha, Hyeon-Seung;Lim, Bum-Soon;Rhee, Sang-Hoon
    • Korean Journal of Dental Materials
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    • v.45 no.4
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    • pp.233-242
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    • 2018
  • The purpose of this study is to evaluate the effect of resin cement color on the color of commercially available zirconia crown. The zirconia and resin cements used for the experiment were $NuSmile^{(R)}$ ZR Zirconia LT Shade (LT), $RelyX^{TM}$ U200 TR, A2, and A3O (TR, A2, A3O). The disks of zirconia and resin cements with diameters of 5 mm and thicknesses of 1 mm were prepared. Five disks were made for each specimen. The CIE $L^*a^*b^*$ values of zirconia, resin cements and the combinations thereof were measured on black and white backgrounds, respectively, using a spectrophotometer. The color effect of resin cement on the color of the zirconia crown was evaluated by calculating translucency parameter (TP), contrast ratio (CR), and color differences (${\Delta}E{^*}_{ab}$) based on the measured CIE $L^*a^*b^*$ values. The statistical significances were verified by one-way ANOVA and the Tukey-multiple comparisons tests. As a result, the TP and CR values were decreased (p<0.05) and increased, respectively, in the combination of zirconia and resin cement disks compared to zirconia disk per se. When using the black background, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of the zirconia and three resin cement disks were imperceptible level. The A3O showed the lowest ${\Delta}E{^*}_{ab}$ value among three resin cements. When using the white background, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and TR resin cement (LT/TR) disks showed acceptable level. However, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and A2 resin cement (LT/A2) disks showed unacceptable level. Meanwhile, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and A3O resin cement (LT/A3O) disks showed perceptible but acceptable level. Within the limits of this study, the colors of resin cements did not cause unacceptable color changes of zirconia except the combination of LT/A2 on the white background. The resin cement that gave the least color changes to zirconia was A3O. This means that the resin cement A3O is recommended to use for minimizing color changes when cementing commercially available zirconia crown to tooth.

Comparison of Attitudes toward Children among Mothers of Young Children and Maternal Grandmothers: With Specific Focus on Ideal Number of Children, Gender Preference, Expectation Old Age Security and Positive and Negative Values of Children (유아 어머니와 외할머니 세대의 자녀관련 인식 비교: 이상적 자녀 수, 자녀의 성별에 대한 선호도, 노후부양에 대한 기대, 긍정적 자녀가치와 부정적 자녀가치를 중심으로)

  • Young-Shin Park ;Uichol Kim ;Mi-Sook Kim
    • Korean Journal of Culture and Social Issue
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    • v.18 no.1
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    • pp.127-152
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    • 2012
  • The research investigates the attitudes toward children among mothers young children and maternal grandmothers, focusing specifically on the ideal number of children, gender preference, old age security and positive and negative values of children. A total of 442 respondents, consisting of 221 young mothers (average age of 35) and 221 maternal grandmothers (average age of 63) completed a questionnaire developed by Kim, Park and Kwon (2005). The reliability of the scales ranged from Cronbach α of .78 to .91. The results are as follows. First, as for the ideal number of children, young mothers reported that they would prefer two children, while grandmothers reported that they would prefer four children. As for the ideal number of male child, young mothers reported that they would prefer that they would prefer one son, while grandmothers reported two sons. Second, as for the gender of the child, young mothers did not show a gender preference, while grandmothers stated that at least one child should be a son, especially if it is the only child. Third, grandmothers had higher expectation of old age security in their male child than young mothers but two groups did not show any difference for the female child. Fourth, as for positive values of children, young mothers were more likely to emphasize personal aspects (i.e., psychological pleasure and happiness) and family cohesiveness, while grandmothers were more likely to emphasize social aspects (i.e., continuing the family line and old age security. As for negative values of children, young mothers were more likely to emphasize personal aspects (i.e., parental role and responsibility), while grandmothers were more likely to emphasize social aspects (i.e., family conflict and relationship). Fifth, as for factors that influenced the number of children that they decided to have, young mothers were more likely to report negative values of children (i.e., financial constraints), while grandmothers were more likely to emphasize positive values of children (i.e., continuing the family line).

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Effect of Accelerated Storage on the Microstructure and Water Absorption Characteristics of Korean Adzuki Bean (Vigna angularis L.) Cultivar (팥의 가속화 저장에 따른 미세구조 및 수분흡수 특성)

  • Jieun Kwak;Seon-Min Oh;You-Geun Oh;Yu-Chan Choi;Hyun-Jin Park;Suk-Bo Song;Jeong-Heui Lee;Jeom-Sig Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.68 no.3
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    • pp.167-174
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    • 2023
  • This study investigated the microstructure and water absorption characteristics of the Korean adzuki bean (Vigna angularis L.) cultivar under accelerated storage. The germination rate, acid value, redness (a*), and yellowness (b*) values showed no significant differences after three months of storage compared to pre-storage under low temperatures (4℃). However, a statistically significant difference was observed under accelerated high temperatures (45℃). In particular, after storage for three months, the germination rate and acid value were 0% and 33.63 mg KOH/100g, respectively, under accelerated high temperatures. After storage for three months, the holes, hilum damage, and spaces between the seed coat and cotyledon shortened the time and speed of water absorption under accelerated high temperatures compared to that under low temperatures. Conversely, further research is required to investigate the reason for the low rate of parallel water absorption.

Influence analysis of Internet buzz to corporate performance : Individual stock price prediction using sentiment analysis of online news (온라인 언급이 기업 성과에 미치는 영향 분석 : 뉴스 감성분석을 통한 기업별 주가 예측)

  • Jeong, Ji Seon;Kim, Dong Sung;Kim, Jong Woo
    • Journal of Intelligence and Information Systems
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    • v.21 no.4
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    • pp.37-51
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    • 2015
  • Due to the development of internet technology and the rapid increase of internet data, various studies are actively conducted on how to use and analyze internet data for various purposes. In particular, in recent years, a number of studies have been performed on the applications of text mining techniques in order to overcome the limitations of the current application of structured data. Especially, there are various studies on sentimental analysis to score opinions based on the distribution of polarity such as positivity or negativity of vocabularies or sentences of the texts in documents. As a part of such studies, this study tries to predict ups and downs of stock prices of companies by performing sentimental analysis on news contexts of the particular companies in the Internet. A variety of news on companies is produced online by different economic agents, and it is diffused quickly and accessed easily in the Internet. So, based on inefficient market hypothesis, we can expect that news information of an individual company can be used to predict the fluctuations of stock prices of the company if we apply proper data analysis techniques. However, as the areas of corporate management activity are different, an analysis considering characteristics of each company is required in the analysis of text data based on machine-learning. In addition, since the news including positive or negative information on certain companies have various impacts on other companies or industry fields, an analysis for the prediction of the stock price of each company is necessary. Therefore, this study attempted to predict changes in the stock prices of the individual companies that applied a sentimental analysis of the online news data. Accordingly, this study chose top company in KOSPI 200 as the subjects of the analysis, and collected and analyzed online news data by each company produced for two years on a representative domestic search portal service, Naver. In addition, considering the differences in the meanings of vocabularies for each of the certain economic subjects, it aims to improve performance by building up a lexicon for each individual company and applying that to an analysis. As a result of the analysis, the accuracy of the prediction by each company are different, and the prediction accurate rate turned out to be 56% on average. Comparing the accuracy of the prediction of stock prices on industry sectors, 'energy/chemical', 'consumer goods for living' and 'consumer discretionary' showed a relatively higher accuracy of the prediction of stock prices than other industries, while it was found that the sectors such as 'information technology' and 'shipbuilding/transportation' industry had lower accuracy of prediction. The number of the representative companies in each industry collected was five each, so it is somewhat difficult to generalize, but it could be confirmed that there was a difference in the accuracy of the prediction of stock prices depending on industry sectors. In addition, at the individual company level, the companies such as 'Kangwon Land', 'KT & G' and 'SK Innovation' showed a relatively higher prediction accuracy as compared to other companies, while it showed that the companies such as 'Young Poong', 'LG', 'Samsung Life Insurance', and 'Doosan' had a low prediction accuracy of less than 50%. In this paper, we performed an analysis of the share price performance relative to the prediction of individual companies through the vocabulary of pre-built company to take advantage of the online news information. In this paper, we aim to improve performance of the stock prices prediction, applying online news information, through the stock price prediction of individual companies. Based on this, in the future, it will be possible to find ways to increase the stock price prediction accuracy by complementing the problem of unnecessary words that are added to the sentiment dictionary.

Metamorphic Evolution of the central Ogcheon Metamorphic Belt in the Cheongju-Miwon area, Korea (청주-미원지역 중부 옥천변성대의 변성진화과정)

  • 오창환;권용완;김성원
    • The Journal of the Petrological Society of Korea
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    • v.8 no.2
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    • pp.106-124
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    • 1999
  • In the Cheongju-Minwon area which occupies the middle part of the Ogcheon Metamorphic Belt, three metamorphic events(M1, M2, M3) had occurred. Intermediate P/T type M2 regional metamorphism formed prevailing mineral assemblages in the study area. Low PIT type M3 contact metamorphism occurred due to the intrusion of granites after M2 metamorphism. M1 metamorphism is recognized by inclusions within garnet. During M2 metamorphism, the metamorphic grade increased from the biotite zone in the southeastern part to the garnet zone in the northwestern part of the study area. This result is similar to the metamorphic evolution of the southwestern part of the Ogcheon Metamorphic Belt. Garnets in the garnet zone are classified into two types; Type A garnet has inclusions whose trail is connected to the foliation in the matrix and Type B garnet has inclusion rich core and inclusion poor rim. Type A garnet formed in the mica rich part with crenulation cleavage whereas Type B garnet formed in the quartz rich part with weak crenulation cleavage. In some outcrops, two types garnets are found together. Compared to the rim of Type A garnet, the rim of Type B garnet is lower in grossular and spessartine contents but higher in almandine and pyrope contents. In some Type B garnets, the inclusion poor part is rimmed by muddy colored or protuberant new overgrowth. In the inclusion poor part and new overgrowth, a rapid increase in grossular and decrease in spessartine is observed. However, the compositional patterns of Type A and B are similar; Ca increases and Mn decreases from core to rim. Two types garnets formed mainly due to the difference of bulk chemistry instead of metamorphic and deformational differences. The metamorphic P-T conditions estimated from Type A garnets are 595-690 OC15.7-8.8 kb, which indicates M2 metamorphism is intermediate P/T type metamorphism. On the other hand, a wide range of P-T conditions is calculated from Type B garnets. The P-T conditions from most Type B garnet rims are 617-690 OC16.2-8.9 kb which also indicates an intermediate P/T type metamorphism. However, at the rim part with flat end or weak overgrowth, grossular content is low and 573-624OC14.7-5.8 kb are estimated. The P-T conditions calculated from plagioclase and biotite inclusions in garnet are 460-500 0C/1.9-3.0 kb. The P-T conditions from rim part with weak overgrowth and inclusions within garnet, indicate that low P/T type M1 regional metamorphism might have occurred before intermediate P/T type M2 regional metamorphism. The P-T conditions estimated from samples which had undergone low PIT type M3 metamorphism strongly, are 547-610 0C/2.1-5.0 kb.

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