• Title/Summary/Keyword: 직접측정법

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An Analysis on the Conditions for Successful Economic Sanctions on North Korea : Focusing on the Maritime Aspects of Economic Sanctions (대북경제제재의 효과성과 미래 발전 방향에 대한 고찰: 해상대북제재를 중심으로)

  • Kim, Sang-Hoon
    • Strategy21
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    • s.46
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    • pp.239-276
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    • 2020
  • The failure of early economic sanctions aimed at hurting the overall economies of targeted states called for a more sophisticated design of economic sanctions. This paved way for the advent of 'smart sanctions,' which target the supporters of the regime instead of the public mass. Despite controversies over the effectiveness of economic sanctions as a coercive tool to change the behavior of a targeted state, the transformation from 'comprehensive sanctions' to 'smart sanctions' is gaining the status of a legitimate method to impose punishment on states that do not conform to international norms, the nonproliferation of weapons of mass destruction in this particular context of the paper. The five permanent members of the United Nations Security Council proved that it can come to an accord on imposing economic sanctions over adopting resolutions on waging military war with targeted states. The North Korean nuclear issue has been the biggest security threat to countries in the region, even for China out of fear that further developments of nuclear weapons in North Korea might lead to a 'domino-effect,' leading to nuclear proliferation in the Northeast Asia region. Economic sanctions had been adopted by the UNSC as early as 2006 after the first North Korean nuclear test and has continually strengthened sanctions measures at each stage of North Korean weapons development. While dubious of the effectiveness of early sanctions on North Korea, recent sanctions that limit North Korea's exports of coal and imports of oil seem to have an impact on the regime, inducing Kim Jong-un to commit to peaceful talks since 2018. The purpose of this paper is to add a variable to the factors determining the success of economic sanctions on North Korea: preventing North Korea's evasion efforts by conducting illegal transshipments at sea. I first analyze the cause of recent success in the economic sanctions that led Kim Jong-un to engage in talks and add the maritime element to the argument. There are three conditions for the success of the sanctions regime, and they are: (1) smart sanctions, targeting commodities and support groups (elites) vital to regime survival., (2) China's faithful participation in the sanctions regime, and finally, (3) preventing North Korea's maritime evasion efforts.

A Study on the Effect of Network Centralities on Recommendation Performance (네트워크 중심성 척도가 추천 성능에 미치는 영향에 대한 연구)

  • Lee, Dongwon
    • Journal of Intelligence and Information Systems
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    • v.27 no.1
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    • pp.23-46
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    • 2021
  • Collaborative filtering, which is often used in personalization recommendations, is recognized as a very useful technique to find similar customers and recommend products to them based on their purchase history. However, the traditional collaborative filtering technique has raised the question of having difficulty calculating the similarity for new customers or products due to the method of calculating similaritiesbased on direct connections and common features among customers. For this reason, a hybrid technique was designed to use content-based filtering techniques together. On the one hand, efforts have been made to solve these problems by applying the structural characteristics of social networks. This applies a method of indirectly calculating similarities through their similar customers placed between them. This means creating a customer's network based on purchasing data and calculating the similarity between the two based on the features of the network that indirectly connects the two customers within this network. Such similarity can be used as a measure to predict whether the target customer accepts recommendations. The centrality metrics of networks can be utilized for the calculation of these similarities. Different centrality metrics have important implications in that they may have different effects on recommended performance. In this study, furthermore, the effect of these centrality metrics on the performance of recommendation may vary depending on recommender algorithms. In addition, recommendation techniques using network analysis can be expected to contribute to increasing recommendation performance even if they apply not only to new customers or products but also to entire customers or products. By considering a customer's purchase of an item as a link generated between the customer and the item on the network, the prediction of user acceptance of recommendation is solved as a prediction of whether a new link will be created between them. As the classification models fit the purpose of solving the binary problem of whether the link is engaged or not, decision tree, k-nearest neighbors (KNN), logistic regression, artificial neural network, and support vector machine (SVM) are selected in the research. The data for performance evaluation used order data collected from an online shopping mall over four years and two months. Among them, the previous three years and eight months constitute social networks composed of and the experiment was conducted by organizing the data collected into the social network. The next four months' records were used to train and evaluate recommender models. Experiments with the centrality metrics applied to each model show that the recommendation acceptance rates of the centrality metrics are different for each algorithm at a meaningful level. In this work, we analyzed only four commonly used centrality metrics: degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality. Eigenvector centrality records the lowest performance in all models except support vector machines. Closeness centrality and betweenness centrality show similar performance across all models. Degree centrality ranking moderate across overall models while betweenness centrality always ranking higher than degree centrality. Finally, closeness centrality is characterized by distinct differences in performance according to the model. It ranks first in logistic regression, artificial neural network, and decision tree withnumerically high performance. However, it only records very low rankings in support vector machine and K-neighborhood with low-performance levels. As the experiment results reveal, in a classification model, network centrality metrics over a subnetwork that connects the two nodes can effectively predict the connectivity between two nodes in a social network. Furthermore, each metric has a different performance depending on the classification model type. This result implies that choosing appropriate metrics for each algorithm can lead to achieving higher recommendation performance. In general, betweenness centrality can guarantee a high level of performance in any model. It would be possible to consider the introduction of proximity centrality to obtain higher performance for certain models.

Perfluorocarbon Does Not Inhibit Chemokine Expression in Airway Epithelial Cells (Perfluorocarbon이 기도 상피세포 Chemokine 발현에 미치는 영향에 관한 연구)

  • Suh, Gee-Young;Kang, Kyeong-Woo;Park, Sang-Joon;Chung, Man-Pyo;Kim, Ho-Joong;Choi, Dong-Chull;Rhee, Chong-H;Kwon, O-Jung
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.2
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    • pp.223-235
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    • 2000
  • Background: Liquid ventilation is associated with decreased inflammatory response in an injured lung. This study was performed to investigate if whether perfluorocarbon(PFC) can decrease chemokine expression in airway epithelial cells. Methods: A549 cells were used for airway epithelial cells and perfluorodecalin for PFC. To expose cells to PFC, lower chamber of Transwell$^{(R)}$plate was used. This study was performed in two parts. In the first part, we examined whether PFC could decrease chemokine expression in airway epithelial cells through inhibition of other inflammatory cells. Peripheral blood mononuclear cells(PBMC's) were isolated and stimulated with lipopolysaccharide(LPS, 10 ${\mu}g/mL$) for 24 hours with or without exposure to PFC. Then A549 cells were stimulated with conditioned media(CM) containing the culture supernatants of PBMC. After 24 hours, the expressions of interleukin-8(IL-8) and RANTES were measured. In the second part of the study, we studied whether PFC could directly suppress chemokine expression in airway epithelial cells. A549 cells were stimulated for 24 hours with interleukin-l$\beta$ and/or tumor necrosis factor-$\alpha$ with or without exposure to PFC, and then the chemokine expression was measured. Northern analysis was used to measure the mRNA expression, and ELISA was used for immunoreactive protein measurements in culture supernatant. Results: 1. IL-8 and RANTES mRNA expression and immunoreactive protein production were increased significantly by CM from LPS-stimulated PBMC in A459 cells compared to with CM from unstimulated PBCM (p<0.05), but exposure of PFC had no significant effect on either mRNA expression or immunoreactive protein expression. 2. IL-8 and RANTES mRNA expression and immunoreactive protein production were increased significantly by IL-1$\beta$ and TNF-$\alpha$ in A549 cells(p<0.05), but exposure of PFC had no significant effect on neither either mRNA expression nor immunoreactive protein production. Conclusion : Decreased chemokine expression of airway epithelial cells may not be involved in decreased inflammatory response observed in liquid ventilation. Further studies on possible mechanisms of decreased inflammatory response are warranted.

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Cutaneous hydration effect of collagen hydrolysate containing collagen tripeptides (콜라겐 트리펩타이드를 고함량으로 함유하는 콜라겐 가수분해물의 피부 보습 효과)

  • Kim, Ae-Hyang;Kim, Yi-Soo;Piao, Zhe;Shin, Yong Chul;Ha, Min Woo
    • Korean Journal of Food Science and Technology
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    • v.50 no.4
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    • pp.420-429
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    • 2018
  • Skin ageing is associated with compromised performance of its fundamental barrier functions, with undesirable changes in appearance. Since this may introduce a detrimental impact on the quality of life, significant effort to discover effective ingredients against ageing is being invested. Recently, collagen hydrolysates containing tripeptides such as GlyPro-Hyp (GPH) have been developed with anticipation of improved effects compared to that of existing collagen hydrolysate-products. To evaluate the cutaneous hydration effect of collagen tripeptides (CTP), meaningful biomarkers in human dermal fibroblasts (HDF) and NC/Nga Tnd mice were analyzed in this study. Increased levels of ceramide kinase, hyaluronic acid, collagen 1A, and hyaluronan synthase-2 (HAS2), and decreased levels of hyaluronidase-1 (HYAL1) and CD44 in HDF cells were demonstrated. Furthermore, significant reduction of transepidermal water loss (TEWL), scratching behavior, HYAL1, $TNF-{\alpha}$ and IL-6 and increased water content and HAS2 were verified by in vivo tests. These results strongly suggest the potential of CTP as a skin hydration agent.

Effect of Antioxidant, Antimutagenicity and Anticancer of Root Extract from Ixeris dentata Nakai (씀바귀 뿌리 추출물의 항산화성, 항돌연변이원성 및 항암활성 효과)

  • Kim, Myong-Jo;Kim, Ju-Sung;Jeong, Dong-Myong;Ham, Seung-Shi;Yu, Chang-Yeon
    • Korean Journal of Medicinal Crop Science
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    • v.10 no.3
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    • pp.222-229
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    • 2002
  • Ixeris dentata root were extracted with methanol and then fractionated with n-hexane, EtOAc and BuOH to get active fractions. and their antioxidant and antimicrobial activities in each fraction were determined. Ethyl acetate fraction of Ixeris dentata root showed strong antioxidant activities, but aqueous fraction did not show any activities. But in the antimicrobial test, aqueous fraction showed strong antimicrobial activities except to Escherichia coli. especially, aqueous fraction showed the strongest activities against Hypocrea nigricans. and butanol fraction showed the strongest activities against Cladosporium herbarum. This study was performed to determine the antimutagenic and cytotoxic effect of Ixeris dentata root methanol extract on Salmonella typhimurium TA98, TA100 and cancer cell lines using ames test and cytotoxicity assay, respectively. Cancer cell lines include human lung carcinoma(A549), human breast adenocarcinoma(MCF-7) and human hepatocellular carcinoma (Hep 3B). Futher fractionations with hexane, ethyl acetate, butanol and water from methanol extract of Ixeris dentata root were performed to obtain effective fraction, methanol extracts showed 79.94% inhibitory effect on the mutagenesis induced by N' -methyl- N' -nitro-N-nitrosoguanidine(MNNG) against TA100, while 89.99% inhibition was observed on the mutagenesis induced by 4-nitroquinoline-1-oxide(4NQO) against TA98. In the meanwhile, butanol fraction showed 89.92% and 71.01% inhibitory effect on the mutagenesis induced by benzo(a)pyrene(B(a)P) against TA98 and TA100, respectively. Ethyl acetate fraction showed the strongest effect against A549, MCF-7 and Hep3B at the same concentration compared to those of other fration.

Quantitative Analysis of Magnetization Transfer by Phase Sensitive Method in Knee Disorder (무릎 이상에 대한 자화전이 위상감각에 의한 정량분석법)

  • Yoon, Moon-Hyun;Sung, Mi-Sook;Yin, Chang-Sik;Lee, Heung-Kyu;Choe, Bo-Young
    • Investigative Magnetic Resonance Imaging
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    • v.10 no.2
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    • pp.98-107
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    • 2006
  • Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.

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Development of 'Carbon Footprint' Concept and Its Utilization Prospects in the Agricultural and Forestry Sector ('탄소발자국' 개념의 발전 과정과 농림 부문에서의 활용 전망)

  • Choi, Sung-Won;Kim, Hakyoung;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.4
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    • pp.358-383
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    • 2015
  • The concept of 'carbon footprint' has been developed as a means of quantifying the specific emissions of the greenhouse gases (GHGs) that cause global warming. Although there are still neither clear definitions of the term nor rules for units or the scope of its estimation, it is broadly accepted that the carbon footprint is the total amount of GHGs, expressed as $CO_2$ equivalents, emitted into the atmosphere directly or indirectly at all processes of the production by an individual or organization. According to the ISO/TS 14067, the carbon footprint of a product is calculated by multiplying the units of activity of processes that emit GHGs by emission factor of the processes, and by summing them up. Based on this, 'carbon labelling' system has been implemented in various ways over the world to provide consumers the opportunities of comparison and choice, and to encourage voluntary activities of producers to reduce GHG emissions. In the agricultural sector, as a judgment basis to help purchaser with ethical consumption, 'low-carbon agricultural and livestock products certification' system is expected to have more utilization value. In this process, the 'cradle to gate' approach (which excludes stages for usage and disposal) is mainly used to set the boundaries of the life cycle assessment for agricultural products. The estimation of carbon footprint for the entire agricultural and forestry sector should take both removals and emissions into account in the "National Greenhouse Gas Inventory Report". The carbon accumulation in the biomass of perennial trees in cropland should be considered also to reduce the total GHG emissions. In order to accomplish this, tower-based flux measurements can be used, which provide a direct quantification of $CO_2$ exchange during the entire life cycle. Carbon footprint information can be combined with other indicators to develop more holistic assessment indicators for sustainable agricultural and forestry ecosystems.

Utility of a forced expiratory flow of 25 to 75 percent as a predictor in children with asthma (소아 천식에서 최대호기중간유량의 기관지 과민성 예측인자로서의 의의)

  • Kang, Jung Wan;Kim, Kyung Won;Kim, Eun Soo;Park, Jun Young;Sohn, Myung Hyun;Kim, Kyu-Earn
    • Clinical and Experimental Pediatrics
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    • v.51 no.3
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    • pp.323-328
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    • 2008
  • Purpose : Asthma is defined as chronic inflammation of the lower small airways, and bronchial hyperreactivity (BHR) is a pathophysiologic feature of asthma. It has been proposed that although there is no direct variable capable of assessing the small airways, a forced expiratory flow of between 25 and 75 percent ($FEF_{25-75}$) might be considered a more sensitive early marker of small airway obstruction than the forced expiratory volume in 1 second ($FEV_1$). Thus, we proposed that the presence and degree of positive responses to bronchial methacholine testing were related to the difference (DFF) and ratio (RFF) between $FEV_1$ and $FEF_{25-75}$ in asthmatic children. Methods : The subjects were 583 symptomatic children, including 324 children with BHR and 259 controls. Pulmonary function tests, methacholine challenge tests, and skin prick tests were performed, and the total eosinophil count, total serum IgE, and serum eosinophil cationic protein level were measured in all subjects. From a concentration-response curve, the methacholine concentration required to produce a decrease of 20% from post-saline $FEV_1$ was calculated ($PC_{20}$). Results : The median DFF and RFF values decreased in controls compared to subjects with bronchial hyperresponsiveness, and this trend was found in groups ranked by its severity. $PC_{20}$ had a negative correlation with DFF and RFF. Cutoff values of 0.5 for DFF and 1.042 for RFF were identified, and sensitivity and specificity were calculated. Conclusion : This study revealed that DFF and RFF might be predictive of bronchial hyperresponsiveness in the context of normal $FEV_1$ in children.

A comparative study on denture cleansers for food stain removal on the denture of elders in domiciliary care (재가복지 노인의치 세정제의 음식물 세정효과 비교연구)

  • Lee, Nam-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.331-336
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    • 2018
  • Oral health is an essential requirement for maintaining and promoting health and quality of life while aging. It is known that there is a deep connection with hygienic management of dentures. However, despite the emphasis on the importance of clean management of dentures, there is a lack of quantitative research on denture-related detergents. Therefore, the purpose of this study is to evaluate food stain removal performance of three denture cleansers containing proteolytic enzymes. In addition, this study provides basic data on self-cleaning methods using detergents and suggests ways to improve effective treatment for oral health of elders in domiciliary care. In order to obtain quantitative data concerning food stain removal performance of each proteinase denture cleaner, the test evaluation method proposed by the Korean Consumer Agency, ISO 20795, was used. A total of 18 specimens were discolored for 48 hours in water dissolved with turmeric, and then washed with each denture cleaner for 24 hours. The cleaned denture specimens were measured quantitatively using a spectrophotometer to measure the color values of the denture specimens before the discoloration as well as the color values of the discolored specimens after cleaning with the denture cleanser. The experimental values were analyzed through one-way ANOVA with post-hoc Tukey's test, and statistically significant differences were found among the experimental groups. It was found that C had statistically significant stain removal performance compared with A and B(p<.05). All experiments were conducted for a total of 21 days, from July 3- 23, 2017. This study confirms that denture cleansers is a beneficial self-denture management method for domiciliary seniors. Therefore, it is necessary to extend accessibility for denture cleansers in order to to optimize domiciliary care for elderly oral hygiene and health.

Food intake and nutritional status of female marriage immigrants residing in Gwangju, Korea (광주지역 결혼이주여성의 식품 및 영양소 섭취 실태)

  • Yang, Eun Ju;Khil, Jin Mo
    • Journal of Nutrition and Health
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    • v.49 no.5
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    • pp.358-366
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    • 2016
  • Purpose: This study was conducted to assess the nutritional status of female marriage immigrants attending Korean language class in Gwangju, Korea by analyzing daily food and nutrient intake. Methods: Eighty-three female immigrants completed a survey. Anthropometric measurements were obtained, and dietary food intake was assessed using a 1-day 24 hour recall method. Results: The average length of residence in Korea was 5.3 years, and mean age of subjects was 31.0 years old. The home countries of subjects were Vietnam (50.6%), China (24.1%), Philippines (13.3%), and others (12%). Due to the length of residence, there were significant differences in body weight (p < 0.05), BMI (p < 0.05), percent body fat (p < 0.05), and diastolic blood pressure (p < 0.05). The subjects who were 30~49 years old consumed more vegetables and less seaweed than the subjects who were 20~29 years old. The other kinds of consumed foods were similar among groups in different age groups or lengths of residence in Korea. Average energy intake of subjects was 1,641.0 Kcal. The group with less than 5 years of residence showed higher cholesterol intake than the group with 5 or more years of residence in Korea (p < 0.05). There was no significant difference in nutrient intake between the groups of different age or length of residence. There was a positive association among dietary cholesterol intake and consumption of eggs, milk. and dairy products, and blood pressure. Conclusion: The study shows that length of residence affects rate of obesity and nutritional status. Further extensive research is needed to understand the effect of dietary changes and nutritional status of female marriage immigrants as well as for their successful adaptation to develop a more active and long-term nutrition education program.