• Title/Summary/Keyword: Statistical Analysis Method

Search Result 5,027, Processing Time 0.051 seconds

Long-term Prognostic Value of Dipyridamole Stress Myocardial SPECT (디피리다몰 부하 심근관류 SPECT의 장기예후 예측능)

  • Lee, Dong-Soo;Cheon, Gi-Jeong;Jang, Myung-Jin;Kang, Won-Jun;Chung, June-Key;Lee, Myoung-Mook;Lee, Myung-Chul;Kang, Wee-Chang;Lee, Young-Jo
    • The Korean Journal of Nuclear Medicine
    • /
    • v.34 no.1
    • /
    • pp.39-54
    • /
    • 2000
  • Purpose: Dipyridamole stress myocardial perfusion SPECT could predict prognosis, however, long-term follow-up showed change of hazard ratio in patients with suspected coronary artery disease. We investigated how long normal SPECT could predict the benign prognosis on the long-term follow-up. Materials and Methods: We followed up 1169 patients and divided these patients into groups in whom coronary angiography were performed and were not. Total cardiac event rate and hard event rate were predicted using clinical, angiographic and SPECT findings. Predictive values of normal and abnormal SPECT were examined using survival analysis with Mantel-Haenszel method, multivariate Cox proportional hazard model analysis and newly developed statistical method to test time-invariance of hazard rate and changing point of this rate. Results: Reversible perfusion decrease on myocardial perfusion SPECT predicted higher total cardiac event rate independently and further to angiographic findings. However, myocardial SPECT showed independent but not incremental prognostic values for hard event rate. Hazard ratio of normal perfusion SPECT was changed significantly (p<0.001) and the changing point of hazard rate was 4.4 years of follows up. However, the ratio of abnormal SPECT was not. Conclusion: Dipyridamole stress myocardial perfusion SPECT provided independent prognostic information in patients with known and suspected coronary artery disease. Normal perfusion SPECT predicted least event rate for 4.4 years.

  • PDF

A Study on Family Planning Rumors & Practice in Rural Communities (일 농촌지역 가족계획 풍문과 실천에 관한 연구)

  • 추수경
    • Journal of Korean Academy of Nursing
    • /
    • v.8 no.2
    • /
    • pp.63-77
    • /
    • 1978
  • Studies pertaining to influential factors on adoption and practice of family planning are very much needed to lower fertility, for family planning has regarded as only one social acceptable means to curb the accelerated population growth. One of the influential factors is known as rumors on family planning methods that hinder the actual practice of family planning. This study generally aimed at disclosing rumors on family planning methods prevalent in rural communities so that one could gain some in sights to cope with the ill effects of rumors to promote family planning Practice in rural communities in Korea. In order to accomplish the general aims this study formulated following four specific objectives; 1. Find out types and frequencies of rumors exposed of contraceptive methods. 2. Find out the relationship between the rumors exposed and socio-economic and demographic characteristics of new village leaders and health workers. 3. Examine the relationship between family planing rumors and family planning practices. The materials for this study were drawn from the two different sets of data gathered in July and Octorber 1977 respectivily by Center for Population & family Planning, Yon sei University. One is current family planning practice among eligible women reaiding in 4 Myuns in Kwang Wha country and the other is Survey on Rumor on family planning method heard by new village leaders and health workers in the four myuns. The four Myuns were divided into 60 small areas. Current family planning practice rate in each small area and as a whole were calculated. The unit of analysis in this study was not the indviduel person but the 55 small areas. Percentage, average, F-Test t-test and a coefficient of correlation were used for statistical analysis. Results of this study could be summarized as follows: 1. Rumors by different method of contraception: Medical complications, gastro-intestinal disorders, and difficulty in usage one most prevalent rumors about oral pills. Around 49% -77% of the 55 areas were often heard and the most frequent rumor was related medical complications of oral pills. Rumors on medical complications and incomplete effect of intrauterines as contraceptive were heard 51-66% of the 55 small areas. Rumors that vasectomy resulted in family problems, for instance infiedelity of spouse were often heard to 44% of the 55 small areas. 2. Rumors by socio-economic and demographic characteristic of new village leader and health workers: Among the demographic characteristics such as sex, age and sex composition of children, sex and age differentials in frequency of rumors heard more observed, Female new village health workers have heard more frequently than male new village leader. (t = 7.137, p> 0.01, d.f. = 53, a coefficient of correlation 0.27, p>0.05) The Younger age group less than 40 years of age have heard rumors of than the group over 40 years old. (t = 7.18, p>0.01, d.f. = 53, a coefficient of correlation 0.27, p>0.05) However, it was not observable that a consistent sex and age differentials in frequency of rumors heard of each contraceptive mettled, But, more female new village health works heard of rumors about intrauterine device than male new village leaders. (t = 0.497, p> 0.01, d.f. = 53, a coefficient of correlatin 0.32, p>0.01) 3. It was found that there was no statistically significant relationship between the frequency of rumors heard and current family planning practices on the whole, However, frequency of rumors heard about vasectomy appeared to have a positive relationship with current practice of vasectomy. A rather consistent pattern of relationship between“requency of rumors heard”and current family practice rate was demonstrated of 10 graphes which showed the relation between the two variagles. The current family planning practice rate in the“never heard”group and “frequently heard”group was equally lower than that in“often heard”group. The relatively consistent ∩ pattern of relationship needs to be farther investigated, for this pattern is different from the relationship that has been assumed to exist between these two variables.

  • PDF

A Study on the Estimation of Values of Individual Services of an Arboretum using the CE Method - Focused on Gyeongnam Arboretum - (CE 기법을 적용한 수목원의 편익제공 가치 추정 연구 - 경남수목원을 대상으로 -)

  • Kang, Kee-Rae
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.41 no.1
    • /
    • pp.51-59
    • /
    • 2013
  • This study was conducted to compare the sizes of effective values, which users recognize, according to the kinds of physical and psychological services provided by an arboretum, by estimating them in monetary values. As an analysis tool for this purpose, the CE(Choice Experiments) method, which is able to estimate effective value's size depending on each variable, was employed. For drawing up profiles for estimation of the values of individual services, 25 profiles were extracted using the orthogonal design of the SPSS statistical package, and questions of 75 pairs were created not to make each of the profiles overlapped. Then, each user was given three questions at five sets each and 3,510 data were used for the analysis. As the result, in relation to the attribute, 'The kinds of trees should be diversified 50% more than now.', firstly, users showed the biggest willingness to pay, based on the present level, and expressed intentions to pay 7,956 won, additionally. Secondly, the value of the path design that was unique than the present road design was estimated in 6,025 won, and when individual attendants guided visitors in the arboretum, they expressed intentions to pay nearly three times more expenses than when they were guided as a group. These results show that users in the Gyeongnam Arboretum recognized the highest effective values towards the collection and display of trees that are arboretum's original functions, and it was followed by the unique road design to observe a variety of dense trees well. This research could be useful in comparing or measuring particular effective values of users that central operators of arboretums want to know. Moreover, it would be suggested as an advanced research for providing basic data about value estimation of individual environmental goods not only in arboretums, but also in other fields.

Single Laboratory Validation and Uncertainty Estimation of a HPLC Analysis Method for Deoxynivalenol in Noodles (면류에서 HPLC를 이용한 데옥시니발레놀 분석법의 검증과 불확도 산정)

  • Ee, Ok-Hyun;Chang, Hyun-Joo;Kang, Young-Woon;Kim, Mee-Hye;Chun, Hyang-Sook
    • Journal of Food Hygiene and Safety
    • /
    • v.26 no.2
    • /
    • pp.142-149
    • /
    • 2011
  • An isocratic high performance liquid chromatography (HPLC) method for routine analysis of deoxynivalenol in noodles was validated and estimated the measurement uncertainty. Noodles (dried noodle and ramyeon) were analyzed by HPLC-ultraviolet detection using immunoaffinity column for clean-up. The limits of detection (LOD) and quantification (LOQ) were 7.5 ${\mu}g$/kg and 18.8 ${\mu}g$/kg, respectively. The calibration curve showed a good linearity, with correlation coefficients $r^2$ of 0.9999 in the concentration range from 20 to 500 ${\mu}g$/kg. Recoveries and Repeatabilities expressed as coefficients of variation (CV) spiked with 200 and 500 ${\mu}g$/kg were $82{\pm}2.7%$ and $87{\pm}1.3%$% in dried noodle, and $97{\pm}1.6%$ and $91{\pm}12.0%$ in ramyeon, respectively. The uncertainty sources in measurement process were identified as sample weight, final volume, and sample concentration in extraction volume as well as components such as standard stock solution, working standard solution, 5 standard solutions, calibration curve, matrix, and instrument. Deoxynivalenol concentration and expanded uncertainty in two matrixes spiked with 200 ${\mu}g$/kg and 500 ${\mu}g$/kg were estimated to be $163.8{\pm}52.1$ and $435.2{\pm}91.6\;{\mu}g$/kg for dried noodle, and $194.3{\pm}33.0$ and $453.2{\pm}91.1\;{\mu}g$/kg for ramyeon using a coverage factor of two which gives a level of statistical confidence with approximately 95%. The most influential component among uncertainty sources was the recovery of matrix, followed by calibration curve.

Social Tagging-based Recommendation Platform for Patented Technology Transfer (특허의 기술이전 활성화를 위한 소셜 태깅기반 지적재산권 추천플랫폼)

  • Park, Yoon-Joo
    • Journal of Intelligence and Information Systems
    • /
    • v.21 no.3
    • /
    • pp.53-77
    • /
    • 2015
  • Korea has witnessed an increasing number of domestic patent applications, but a majority of them are not utilized to their maximum potential but end up becoming obsolete. According to the 2012 National Congress' Inspection of Administration, about 73% of patents possessed by universities and public-funded research institutions failed to lead to creating social values, but remain latent. One of the main problem of this issue is that patent creators such as individual researcher, university, or research institution lack abilities to commercialize their patents into viable businesses with those enterprises that are in need of them. Also, for enterprises side, it is hard to find the appropriate patents by searching keywords on all such occasions. This system proposes a patent recommendation system that can identify and recommend intellectual rights appropriate to users' interested fields among a rapidly accumulating number of patent assets in a more easy and efficient manner. The proposed system extracts core contents and technology sectors from the existing pool of patents, and combines it with secondary social knowledge, which derives from tags information created by users, in order to find the best patents recommended for users. That is to say, in an early stage where there is no accumulated tag information, the recommendation is done by utilizing content characteristics, which are identified through an analysis of key words contained in such parameters as 'Title of Invention' and 'Claim' among the various patent attributes. In order to do this, the suggested system extracts only nouns from patents and assigns a weight to each noun according to the importance of it in all patents by performing TF-IDF analysis. After that, it finds patents which have similar weights with preferred patents by a user. In this paper, this similarity is called a "Domain Similarity". Next, the suggested system extract technology sector's characteristics from patent document by analyzing the international technology classification code (International Patent Classification, IPC). Every patents have more than one IPC, and each user can attach more than one tag to the patents they like. Thus, each user has a set of IPC codes included in tagged patents. The suggested system manages this IPC set to analyze technology preference of each user and find the well-fitted patents for them. In order to do this, the suggeted system calcuates a 'Technology_Similarity' between a set of IPC codes and IPC codes contained in all other patents. After that, when the tag information of multiple users are accumulated, the system expands the recommendations in consideration of other users' social tag information relating to the patent that is tagged by a concerned user. The similarity between tag information of perferred 'patents by user and other patents are called a 'Social Simialrity' in this paper. Lastly, a 'Total Similarity' are calculated by adding these three differenent similarites and patents having the highest 'Total Similarity' are recommended to each user. The suggested system are applied to a total of 1,638 korean patents obtained from the Korea Industrial Property Rights Information Service (KIPRIS) run by the Korea Intellectual Property Office. However, since this original dataset does not include tag information, we create virtual tag information and utilized this to construct the semi-virtual dataset. The proposed recommendation algorithm was implemented with JAVA, a computer programming language, and a prototype graphic user interface was also designed for this study. As the proposed system did not have dependent variables and uses virtual data, it is impossible to verify the recommendation system with a statistical method. Therefore, the study uses a scenario test method to verify the operational feasibility and recommendation effectiveness of the system. The results of this study are expected to improve the possibility of matching promising patents with the best suitable businesses. It is assumed that users' experiential knowledge can be accumulated, managed, and utilized in the As-Is patent system, which currently only manages standardized patent information.

Mobility Change around Neighborhood Parks and Green Spaces before and after the Outbreak of the COVID-19 Pandemic (COVID-19 발생 전·후 생활권 공원녹지 모빌리티 변화 분석)

  • Choi, Ga yoon;Kim, Yong gook;Kwon, Oh kyu;Yoo, Ye seul
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.51 no.4
    • /
    • pp.101-118
    • /
    • 2023
  • During the COVID-19 pandemic, the utilization rate of neighborhood parks and green spaces increased significantly, and the outbreak served as an opportunity to highlight the values and functions of neighborhood parks and green spaces for urban residents. This study aims to empirically analyze how citizens' movement and the use of neighborhood parks and green spaces changed before and after COVID-19 and examine the social and spatial characteristics that affected these changes. As a research method, first, people's mobility around neighborhood parks and green spaces before and after the COVID-19 pandemic were compared using signal data from telecommunication carriers. Through the analysis of changes in residence time and movement volume, the movement characteristics of citizens after COVID-19 and changes in walking-based park visits were examined. Second, the factors affecting the mobility change in neighborhood parks and green spaces were analyzed. The social and spatial characteristics that affect citizens' visits to neighborhood parks and green spaces before and after COVID-19 were examined through correlation and multiple regression analysis. Subsequently, through cluster analysis, the types of living areas for the post-COVID era were classified from the perspective of the supply and management of neighborhood parks and green spaces services, and directions for improving neighborhood parks and green spaces by type were presented. Major research findings are as follows: First, since the outbreak of COVID-19, activities within 500m of the residence have increased. The amount of stay and walking movement increased in both 2020 and 2021, which means that the need to review the quantitative standards and attractions of neighborhood parks and green spaces has increased considering the changed scope of the walking and living area. Second, the overall number of visits to neighborhood parks and green spaces by walking has increased since the outbreak of COVID-19. The number of visits to neighborhood parks and green spaces centered on the house and the workplace increased significantly. The park green policy in the post-COVID era should be promoted by discovering underprivileged areas, focusing on areas where residential, commercial, and business facilities are concentrated, and improving neighborhood parks and green services in quantitative and qualitative terms. Third, it was found that the higher the level of park green service, the higher the amount of walking movement. It is necessary to use indicators that contribute to improving citizens' actual park green services, such as walking accessibility, rather than looking at the criteria for securing green areas. Fourth, as a result of cluster analysis, five types of neighborhood parks and green spaces were derived in response to the post-COVID era. This suggests that it is necessary to consider the socioeconomic status and characteristics of living areas and the level of park green services required in future park green policies. This study has academic and policy significance in that it has laid the basis for establishing neighborhood parks and green spaces policy in response to the post-COVID era by using various analysis methodologies such as carrier signal data analysis, GIS analysis, and statistical analysis.

The Effect of Polypropylene Mulching Method on Growth of Quercus glauca Thunb. Seedling and Weed Treatments (부직포 멀칭 방식에 따른 종가시나무 묘목의 생장과 제초에 미치는 영향)

  • Sung, Chang-Hyun;Yoon, Jun-Hyuck;Jin, Eon-Ju;Bae, Eun-Ji
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.48 no.5
    • /
    • pp.59-66
    • /
    • 2020
  • Recently, cultivation and management technologies have been needed to adapt due to climate change, which is causing abnormal weather conditions. One technique is to increase the utilization of evergreen broad-leaved species with high ornamental value. A total of five treatments were installed (1m×22.5m), including 60g/㎡ and 80g/㎡ using two types mulching material with an overlapping and hole-drilling mulching method and these were compared to un-mulching treatment a total of planted 92㎡ attheWol-aTestSiteForestattheForestforBiomaterialsResearchCenterinJinju-si, Gyeongsangnam-dofor 10monthsusing3-years-oldQuercusglaucaThunb. In comparison with the control site, the 60g/㎡ overlapping method was about 1.9 times higher than the root collar diameter, but there was no statistical significance between the treatments. Healthy seedlings were found to meet these conditions due to high biomass values and below and T/R ratios of 3.0 or lower and H/D ratios of 7.0 or lower. Comparing the values of LWR, SWR, and RWR, which can be evaluated for seedling due to the mulching treatments, as compared to the control, the growth of the ground areas including leaves and stems was enhanced, but the growth of the underground areas containing roots tended to have high control values. Based on this, the SQI value, which can be evaluated for the comprehensive quality of seedlings, was found to be significantly different between the control site and the mulching treatment sites, confirming that the growth and growth improvement effects were achieved with mulching treatments. The chlorophyll content analysis showed that there was a significant difference from the control site, and it was judged that weed generation in the control acted as an environmental stress, causing a decrease in chlorophyll content. It was found that the overlapping 80g/㎡ of polypropylene mulching material generated about 4 times fewer weeds than the control, and the manpower required for the mulching test field and weeding were equal at 3.3 people/100㎡/1 day. Mulching treatments have demonstrated a significant difference in the promotion of growth and quality of the seedlings and are judged as an alternative that can reduce the economic burden incurred by the purchase of the supplies and the manpower required to weed forestry plantations.

Estimation of the Accuracy of Genomic Breeding Value in Hanwoo (Korean Cattle) (한우의 유전체 육종가의 정확도 추정)

  • Lee, Seung Soo;Lee, Seung Hwan;Choi, Tae Jeong;Choy, Yun Ho;Cho, Kwang Hyun;Choi, You Lim;Cho, Yong Min;Kim, Nae Soo;Lee, Jung Jae
    • Journal of Animal Science and Technology
    • /
    • v.55 no.1
    • /
    • pp.13-18
    • /
    • 2013
  • This study was conducted to estimate the Genomic Estimated Breeding Value (GEBV) using Genomic Best Linear Unbiased Prediction (GBLUP) method in Hanwoo (Korean native cattle) population. The result is expected to adapt genomic selection onto the national Hanwoo evaluation system. Carcass weight (CW), eye muscle area (EMA), backfat thickness (BT), and marbling score (MS) were investigated in 552 Hanwoo progeny-tested steers at Livestock Improvement Main Center. Animals were genotyped with Illumina BovineHD BeadChip (777K SNPs). For statistical analysis, Genetic Relationship Matrix (GRM) was formulated on the basis of genotypes and the accuracy of GEBV was estimated with 10-fold Cross-validation method. The accuracies estimated with cross-validation method were between 0.915~0.957. In 534 progeny-tested steers, the maximum difference of GEBV accuracy compared to conventional EBV for CW, EMA, BT, and MS traits were 9.56%, 5.78%, 5.78%, and 4.18% respectively. In 3,674 pedigree traced bulls, maximum increased difference of GEBV for CW, EMA, BT, and MS traits were increased as 13.54%, 6.50%, 6.50%, and 4.31% respectively. This showed that the implementation of genomic pre-selection for candidate calves to test on meat production traits could improve the genetic gain by increasing accuracy and reducing generation interval in Hanwoo genetic evaluation system to select proven bulls.

Comparative Volume Measuring Methods According to the Tumor Characters in PET/CT (PET/CT 검사에서 종양의 특성에 따른 체적 측정 방법 비교)

  • Choi, Yong Hoon;Ban, Yung Gak;Oh, Shin Hyun;Lim, Han Sang;Kim, Jae Sam
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.20 no.1
    • /
    • pp.52-58
    • /
    • 2016
  • Purpose Recent retrospective studies are being actively conducted to analyze the survival of patients with SUVmax, MTV, TLG, such as information from a variety of PET originating. However, there is no clear way is difficult to accurately measure the volume of the tumor may be the difference between the caster is raised. In this study, to evaluate compare the volume measuring methods according to the characteristics of the tumor. Materials and Methods 18F-saline to fill the NEMA IEC Body Phantom insert the volume of balance and imbalance in phantom were acquired to the Biograph truepoint 40 (Siemens medical system, Germany) PET/CT scanner. The ratio of the volume and Background was acquired as 3.0, 5.0, 8.0, 18, 40. Clinical patients were randomly selected 120 people in staging patients with cancer of the digestive system from the year 2010 until the year 2014. Measurement methods were used a 40% threshold, 50% threshold and gradient segmentation technique, i.e. PET EDGE. Five years of experience of the two radio-technologist and one doctor was measured by repeated three times. Analysis methods were Intraclass correlation coefficient and Pearson correlation. Results In Phantoms, the 40% threshold method gave the best concordance between measured and actual volumes (r = 0.992, 0.997). In clinical patient outcome agreement between observers EDGE it is as high as 0.999 (CI: 0.998-0.999). And there were no statistical significance of the difference between the measurements (P = 0.620). 40% threshold method showed the best correlation between the measurements (r = 0.953). Increasing the ratio of tumor to background decreased the influence of a measuring method. Conclusion How to measure volume of the tumor in the patient was clinically most useful is 50% and the lowest impact on the characteristics of the tumor. Therefore, to reduce the background of the patients in PET/CT scan, it should be required research and effort.

  • PDF

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

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