• Title/Summary/Keyword: 교차비

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Effect of Physical Control Technology on Aspergillus ochraceus Reduction (물리적 제어기술이 Aspergillus ochraceus 저감화에 미치는 영향)

  • Lee, Eun-Seon;Kim, Jong-Hui;Kim, Bu-Min;Oh, Mi-Hwa
    • Journal of Food Hygiene and Safety
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    • v.36 no.5
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    • pp.447-453
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    • 2021
  • In this study, the effectiveness of physical control technology, a combined light sterilization (LED, UV) and hot water treatment in reducing Aspergillus ochraceus for food production environment was investigated. In brief, 1 mL aliquot of A. ochraceus spore suspension (107-8 spore/mL) was inoculated onto stainless steel chips, which was then dried at 37℃, and each was subjected to different physical treatment. Treatments were performed for 0.5, 1, 2, 5, 8, and 11 hours to reduce the strains using a light-emitting diode, but no significant difference was confirmed among the treatments. However, a significant reduction was observed on the chips treated with UV-C exposure and hot water immersion. After being treated solely with 360 kJ/m2 of UV-C on stainless steel chip, the fungi were significantly reduced to 1.27 log CFU/cm2. Concerning the hot water treatment, the initial inoculum amount of 6.49 log CFU/cm2 was entirely killed by immersion in 83℃ water for 5 minutes. Maintaining a high temperature for 5 minutes at the site is difficult. Thus, considering economic feasibility and usability, we attempted to confirm the appropriate A. ochraceus reduction conditions by combining a relatively low temperature of 60℃ and UV rays. With the combined treatments, even in lukewarm water, A. ochraceus decreased significantly through the increases in the immersion time and the amount of UV-C irradiation, and the yield was below the detection limit. Based on these results, if work tools are immersed in 60℃ lukewarm water for 3 minutes and then placed in a UV sterilization device for more than 10 minutes, the possibility of A. ochraceus cross-contamination during work is expected to be reduced.

Comparative Assessment of Linear Regression and Machine Learning for Analyzing the Spatial Distribution of Ground-level NO2 Concentrations: A Case Study for Seoul, Korea (서울 지역 지상 NO2 농도 공간 분포 분석을 위한 회귀 모델 및 기계학습 기법 비교)

  • Kang, Eunjin;Yoo, Cheolhee;Shin, Yeji;Cho, Dongjin;Im, Jungho
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1739-1756
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    • 2021
  • Atmospheric nitrogen dioxide (NO2) is mainly caused by anthropogenic emissions. It contributes to the formation of secondary pollutants and ozone through chemical reactions, and adversely affects human health. Although ground stations to monitor NO2 concentrations in real time are operated in Korea, they have a limitation that it is difficult to analyze the spatial distribution of NO2 concentrations, especially over the areas with no stations. Therefore, this study conducted a comparative experiment of spatial interpolation of NO2 concentrations based on two linear-regression methods(i.e., multi linear regression (MLR), and regression kriging (RK)), and two machine learning approaches (i.e., random forest (RF), and support vector regression (SVR)) for the year of 2020. Four approaches were compared using leave-one-out-cross validation (LOOCV). The daily LOOCV results showed that MLR, RK, and SVR produced the average daily index of agreement (IOA) of 0.57, which was higher than that of RF (0.50). The average daily normalized root mean square error of RK was 0.9483%, which was slightly lower than those of the other models. MLR, RK and SVR showed similar seasonal distribution patterns, and the dynamic range of the resultant NO2 concentrations from these three models was similar while that from RF was relatively small. The multivariate linear regression approaches are expected to be a promising method for spatial interpolation of ground-level NO2 concentrations and other parameters in urban areas.

Analysis of the Manufacturing Techniques for the KwangDahoe Tying on the Sword in Joseon Dynasty (조선시대 도검 패용 광다회의 제작기법 분석)

  • Baek, Je-Sun;Chung, Kwang-Young
    • Korean Journal of Heritage: History & Science
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    • v.50 no.3
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    • pp.64-87
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    • 2017
  • Dahoe is a traditional braid in Joseon Dynasty. There are many Dahoe artifacts, which can give us a glimpse of the costume, culture, and life of that era. The study of Dahoe is necessary in various fields, but it is difficult because this manufacturing technique has been passed down from hand to hand. Few studies have been done so far. This research examines the manufacturing technique of KwangDahoe which is passed down by Maedeupjang (Decorative Knotting) and is generally used for knotting and/or tying objects. The main characteristic of TieKwangDahoe, made through the same method as WonDahoe, is the square hole in the middle. It was impossibile to remake the original braid because there is no confirmed number of the strand. Especially it is very difficult to do conservation and restoration on serious degradation state of the fiber. Therefore, it is necessary to analyze the non-destructive manufacturing techniques method for Dahoe and assess their applicability. First, we analyzed the artifacts' manufacturing technique based on the database of the Dahoe's manufacturing technique. In order to do that, we undertook schematization, restoration, morphological analyzation of the Dahoe. And then, X-ray CT scans were performed to improve the reliability of the DB. These results of scanning were interpreted based on the manufacturing technique. The selected Tie-KwangDahoe on the sword for the study are artifacts including artistic value and symbolism in Joseon Dynasty. Based on the analysis of the manufacturing technique, we found that both artifacts were made of 20-strand braid of single cross according to the length-scale measure. It was manufactured using 8-strand on left-right side, 12-strand on front-back side by the braiding manufacturing technique method Finally, this research suggests non-destructive analysis method of Dahoe's manufacturing technique is based on the database and the analysis results. I hope this research can be useful in various professional fields of Dahoe in the future. Moreover, I hope this can be of any help in preserving Korean cultural heritage.

The Characteristics of Child and Adolescent Suicide Attempters Admitted to a University Hospital (일 대학병원에 자살 시도 후 입원한 소아청소년들의 특성)

  • Bang, Yeon-Sik;Lee, Jinhee;Min, Seongho;Ahn, Joung-Sook;Park, Ki-Chang;Kim, Min-Hyuk
    • Korean Journal of Psychosomatic Medicine
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    • v.26 no.2
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    • pp.135-144
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    • 2018
  • Objectives : The purpose of this study was to identify the differences of demographic and clinical characteristics between child-adolescents who received medical inpatient care and non-hospitalized adolescents after suicide attempts. Methods : The study included 35 child-adolescents who were hospitalized (Admission group) and 114 child-adolescents who were not hospitalized (Non-Admission group) as a result of a suicide attempt from 2009 to 2015. We compared sociodemographic, clinical, and suicide attempt-related characteristics through a chi-square test and logistic regression analysis to evaluate the differences between the two groups. Results : Child-adolescents of this study most commonly attempted suicide by poisoning, and for motivation of interpersonal problems. Admission group had significantly fewer attempts through injury by sharp objects (${\chi}^2=4.374$, p=0.037) and attempted suicide with a higher chance of actually dying when compared to Risk-Rescue Rating Scale (t=1.981, p=0.049). In addition, Admission group had relatively common motivation for academic problems (${\chi}^2=12.082$, p=0.001) and less motivation for interpersonal difficulties. (${\chi}^2=9.869$, p=0.002) Psychiatric diagnosis at the time of visiting the emergency department showed higher rates of depression in the admission group than Non-Admission group (${\chi}^2=8.649$, p=0.003). The results of logistic regression showed that depression affects hospitalization (OR=2.783, 95% CI 1.092-7.089, p=0.032). Conclusions : This study is meaningful in that it revealed the social and clinical characteristics of all child-adolescents who were hospitalized at a university hospital after attempting suicide. This study identified differences in motivation, methods, and psychiatric diagnosis of hospitalized adolescents and those who were not. Therefore, the results may help adolescent suicide attempters to get a discriminatory approach based on their admission.

Detection of Surface Changes by the 6th North Korea Nuclear Test Using High-resolution Satellite Imagery (고해상도 위성영상을 활용한 북한 6차 핵실험 이후 지표변화 관측)

  • Lee, Won-Jin;Sun, Jongsun;Jung, Hyung-Sup;Park, Sun-Cheon;Lee, Duk Kee;Oh, Kwan-Young
    • Korean Journal of Remote Sensing
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    • v.34 no.6_4
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    • pp.1479-1488
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    • 2018
  • On September 3rd 2017, strong artificial seismic signals from North Korea were detected in KMA (Korea Meteorological Administration) seismic network. The location of the epicenter was estimated to be Punggye-ri nuclear test site and it was the most powerful to date. The event was not studied well due to accessibility and geodetic measurements. Therefore, we used remote sensing data to analyze surface changes around Mt. Mantap area. First of all, we tried to detect surface deformation using InSAR method with Advanced Land Observation Satellite-2 (ALOS-2). Even though ALOS-2 data used L-band long wavelength, it was not working well for this particular case because of decorrelation on interferogram. The main reason would be large deformation near the Mt. Mantap area. To overcome this limitation of decorrelation, we applied offset tracking method to measure deformation. However, this method is affected by window kernel size. So we applied various window sizes from 32 to 224 in 16 steps. We could retrieve 2D surface deformation of about 3 m in maximum in the west side of Mt. Mantap. Second, we used Pleiadas-A/B high resolution satellite optical images which were acquired before and after the 6th nuclear test. We detected widespread surface damage around the top of Mt. Mantap such as landslide and suspected collapse area. This phenomenon may be caused by a very strong underground nuclear explosion test. High-resolution satellite images could be used to analyze non-accessible area.

A Study of the Material Properties of Steel Used to Repair the Stupa of State Preceptor Jigwang from Beopcheonsa Temple, Wonju in 1957 (1957년 원주 법천사지 지광국사탑 수리에 사용된 철물(鐵物)의 재료학적 특성 연구)

  • You, Harim;Lee, Jaesung;Lee, Taejong;Park, Heejeoung
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.100-117
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    • 2020
  • National Treasure no. 101, the stupa of State Preceptor Jigwang from the Beopcheonsa Temple Site in Wonju has been transferred from place to place and reassembled several times since it was built. In particular, overall dismantling and repair was carried out in 1957 to restore parts damaged by bombing during the Korean War. Documented information on the repair process and materials used at that time does not exist. However, various types of metal materials used for this stupa have been identified during conservation work. Besides clamps anchor bolts, 9mm-thick circular rebars were mainly used for joining the parts of this stupa, while circular rebars and wires of various thicknesses were used for joining the parts with mortar restoration materials. Although deformed bars are typically used for stone pagodas classified as architectural structures, smooth circular rebars were used in this case. In terms of restoration using mortar, material shapes were transformed, bound alternately, and twisted irregularly to improve bonding strength and coherence in order to insert restoration materials and to bolster structural weaknesses. In addition, metallographic analysis showed the material to be hypo-eutectoid steel with low carbon content. Many non-metallic inclusions in the shape of drops of different sizes were included, which do not affect the whole elemental composition due to the very small quantities involved. Qualitative and EPMA analysis of Mn and S, which were not identified by SEM-EDS area analysis, established an even distribution of MnS in crystal grains of the microstructure, regardless of the shape of the samples. It is presumed that secondary homogenization and softening might have been conducted after manufacturing to facilitate the working process. Furthermore, in consideration of properties indicating that the thinner the steel is, the less carbon content contained and the greater the elasticity and elongation, it is judged that restoration work was ordered.

The impact of functional brain change by transcranial direct current stimulation effects concerning circadian rhythm and chronotype (일주기 리듬과 일주기 유형이 경두개 직류전기자극에 의한 뇌기능 변화에 미치는 영향 탐색)

  • Jung, Dawoon;Yoo, Soomin;Lee, Hyunsoo;Han, Sanghoon
    • Korean Journal of Cognitive Science
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    • v.33 no.1
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    • pp.51-75
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    • 2022
  • Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation that is able to alter neuronal activity in particular brain regions. Many studies have researched how tDCS modulates neuronal activity and reorganizes neural networks. However it is difficult to conclude the effect of brain stimulation because the studies are heterogeneous with respect to the stimulation parameter as well as individual difference. It is not fully in agreement with the effects of brain stimulation. In particular few studies have researched the reason of variability of brain stimulation in response to time so far. The study investigated individual variability of brain stimulation based on circadian rhythm and chronotype. Participants were divided into two groups which are morning type and evening type. The experiment was conducted by Zoom meeting which is video meeting programs. Participants were sent experiment tool which are Muse(EEG device), tdcs device, cell phone and cell phone holder after manuals for experimental equipment were explained. Participants were required to make a phone in frount of a camera so that experimenter can monitor online EEG data. Two participants who was difficult to use experimental devices experimented in a laboratory setting where experimenter set up devices. For all participants the accuracy of 98% was achieved by SVM using leave one out cross validation in classification in the the effects of morning stimulation and the evening stimulation. For morning type, the accuracy of 92% and 96% was achieved in classification in the morning stimulation and the evening stimulation. For evening type, it was 94% accuracy in classification for the effect of brain stimulation in the morning and the evening. Feature importance was different both in classification in the morning stimulation and the evening stimulation for morning type and evening type. Results indicated that the effect of brain stimulation can be explained with brain state and trait. Our study results noted that the tDCS protocol for target state is manipulated by individual differences as well as target state.

Politics of "Imagined Ethnicity" in World Music (월드뮤직에서 "상상된 민족"의 정치학)

  • Kim, Hee-sun
    • (The) Research of the performance art and culture
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    • no.22
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    • pp.223-252
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    • 2011
  • If we remember that modern world history has built systems of meaning through the concepts "difference," "different," and "other-ness" and has constructed new identity based on opposing hierarchy, music anthropology which tried to build "difference" between the west and the non-west was thoroughly west -centered, in the sense that it has perceived the heterogeneous symbolic systems among nations, as well as the barrier between the two cultures. On the other hand, world music, which has emerged as the most attractive field in culture industry and concert-art-market by crossing over global capitals, markets, and barriers, can be considered the most post-modernist and glocal. However, it is interesting to note that world music, which has been described as post-modern and glocal, has "difference" and "different" in its basis, just like the precepts for modern music anthropology (Meintjes 1990; Guilbault 1993; Taylor 1997; Frith 2000; Feld 1988). Furthermore, one can understand that the "different" and "difference," generally termed as being "non-western," are fundamentally based on ethnic or national imagination. In this sense it is interesting and important to examine such ethnic imagination in the "non-western ethnic musics" in music anthropology and in world music. Notwithstanding the attention paid and research made by music anthropologists, they have failed to elevate the "non-western ethnic musics" to become universally communicative, and these ethnic musics were reborn as "global" and "world music," through the process of "acculturation," "derivation," and "hybridization," with the west as major site for production and consumption. Meanwhile, the audience for world music, which did not exist before the birth of world music as a term, was now born as world music emerged. They are global populace who consume the musical "difference" and "imagined ethnicity," who through their consumption are constructing new social meanings including ethnicity, race, nation, and class identity. This study, by examining current discourse, performance, and process for the world music through media and field studies and scholarly debates, attempts to understand the production and consumption of "imagined ethnicity." This will also shed light on how "ethnicity" is created and consumed, and how this is involved in the process of world music.

Gap-Filling of Sentinel-2 NDVI Using Sentinel-1 Radar Vegetation Indices and AutoML (Sentinel-1 레이더 식생지수와 AutoML을 이용한 Sentinel-2 NDVI 결측화소 복원)

  • Youjeong Youn;Jonggu Kang;Seoyeon Kim;Yemin Jeong;Soyeon Choi;Yungyo Im;Youngmin Seo;Myoungsoo Won;Junghwa Chun;Kyungmin Kim;Keunchang Jang;Joongbin Lim;Yangwon Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1341-1352
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    • 2023
  • The normalized difference vegetation index (NDVI) derived from satellite images is a crucial tool to monitor forests and agriculture for broad areas because the periodic acquisition of the data is ensured. However, optical sensor-based vegetation indices(VI) are not accessible in some areas covered by clouds. This paper presented a synthetic aperture radar (SAR) based approach to retrieval of the optical sensor-based NDVI using machine learning. SAR system can observe the land surface day and night in all weather conditions. Radar vegetation indices (RVI) from the Sentinel-1 vertical-vertical (VV) and vertical-horizontal (VH) polarizations, surface elevation, and air temperature are used as the input features for an automated machine learning (AutoML) model to conduct the gap-filling of the Sentinel-2 NDVI. The mean bias error (MAE) was 7.214E-05, and the correlation coefficient (CC) was 0.878, demonstrating the feasibility of the proposed method. This approach can be applied to gap-free nationwide NDVI construction using Sentinel-1 and Sentinel-2 images for environmental monitoring and resource management.

Effect of food-related lifestyle, and SNS use and recommended information utilization on dining out (혼밥 및 외식소비 관련 식생활라이프스타일과 SNS 이용 및 추천정보활용의 영향)

  • Jin A Jang
    • Journal of Nutrition and Health
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    • v.56 no.5
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    • pp.573-588
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    • 2023
  • Purpose: This study aimed to examine social networking service (SNS) use and recommended information utilization (SURU) according to the food-related lifestyles (FRLs) of consumers and analyze how the interaction between the FRL and SURU affects the practice of eating alone and visiting restaurants. Methods: Data on 4,624 adults in their 20s to 50s were collected from the 2021 Consumer Behavior Survey for Food. Statistical methods included factor analysis, K-means cluster analysis, the complex samples general linear model, the complex samples Rao-Scott χ2 test, and the general linear model. Results: The following three factors were extracted from the FRL data: Convenience pursuit, rational consumption pursuit, and gastronomy pursuit, and the subjects were classified into three groups, namely the rational consumption, convenient gastronomy, and smart gourmet groups. An examination of the difference in SURU according to the FRL showed that the smart gourmet group had the highest score. The result of analyzing the effects of the FRL and SURU on eating alone revealed that both the main effect and the interaction effect were significant (p < 0.01, p < 0.001). The higher the SURU, the higher the frequency of eating alone in the convenience pursuit, and gastronomy pursuit groups. The main and interaction effects of the FRL and SURU on the frequency of eating out were also significant (p < 0.01, p < 0.001). In all the FRL groups, the higher the SURU level, the higher the frequency of visiting restaurants. Specifically, the two groups with convenience and gastronomic tendencies showed a steeper increase. Conclusion: This study provides important basic data for research on consumer behavior related to food SNS, market segmentation of restaurant consumers, and development of marketing strategies using SNS in the future.