• 제목/요약/키워드: Difference Means

검색결과 2,667건 처리시간 0.027초

뇌경색 시기별 MR영상의 정량적 분석 (Quantitative Analysis of MR Image in Cerebral Infarction Period)

  • 박병래;하광;김학진;이석홍;전계록
    • 대한방사선기술학회지:방사선기술과학
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    • 제23권1호
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    • pp.39-47
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    • 2000
  • In this study, we showed a comparison and analysis making use of DWI(diffusion weighted image) using early diagnosis of cerebral Infarction and with the classified T2 weighted image, FLAIR images signal intensity for brain infarction period. period of cerebral infarction after the condition of a disease by ischemic stroke. To compare 3 types of image, we performed polynomial warping and affined transform for image matching. Using proposed algorithm, calculated signal intensity difference between T2WI, DWI, FLAIR and DWI. The quantification values between hand made and calculated data are almost the same. We quantified the each period and performed pseudo color mapping by comparing signal intensity each other according to previously obtained hand made data, and compared the result of this paper according to obtained quantified data to that of doctors decision. The examined mean and standard deviation for each brain infarction stage are as follows ; the means and standard deviations of signal intensity difference between DWI and T2WI for each period are $197.7{\pm}6.9$ in hyperacute, $110.2{\pm}5.4$ in acute, and $67.8{\pm}7.2$ in subacute. And the means and standard deviations of signal intensity difference between DWI and FLAIR for each period are $199.8{\pm}7.5$ in hyperacute, $115.3{\pm}8.0$ in acute, and $70.9{\pm}5.8$ in subacute. We can quantificate and decide cerebral infarction period objectively. According to this study, DWI is very exact for early diagnosis. We classified the period of infarction occurrence to analyze the region of disease and normal region in DW, T2WI, FLAIR images.

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초등교사의 학생의 과학과 교수학습에 대한 곤란도 연구 (A Study on the Degree of Difficulty in the Elementary School Science Teaching and Learning)

  • 정효해;김재영
    • 한국초등과학교육학회지:초등과학교육
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    • 제24권5호특별호
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    • pp.531-538
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    • 2005
  • The primary purpose of the study was to investigate the degree of difficulty and the causes of the difficulties in science instruction reported by elementary teachers and students. The secondary purpose was to suggest the effective methods to both of them to improve the efficiency of science instruction. For this study, the survey was carried out on 322 students and 156 teachers in the 3rd, 4th, and 5th grades. The questionnaires consisted of interest, difficulty and its factors. The results of this investigation are summarized as follows; 1. Teachers had relatively higher interest than students in science instruction content(textbook). Furthermore, the units that teachers showed interest differed from those that students had. This means that there is a significant difference of interest in instruction process between teachers and students. 2. Teachers felt much higher difficulty than students in the content of science instruction. This shows that the degree of interest might have little relation with that of difficulty, and that teaching of science seemed more difficult than teaming. Moreover, there was a difference of difficulty in the units between the teachers and students. The result shows a distinctive difference of difficulty in 8 units of the 3rd grade, 9 units n the 4th grade, and 12 units in the 5th grade (p<.05, p<.001, p<.005, respectively). It means that the difficulty depended on the units. 3. Students responded that they are responsible for difficulty factors of teaming, otherwise teachers thought that students are responsible for it, when the factors were divided into student factor, teacher factor, and curriculum factor. 4. Students demanded many experiments in the lab as well as easy and interesting instructions in order to reduce the degree of difficulty and to improve the condition of science instructions. However, teachers demanded the expansion of experimental equipments and materials as well as the improvement of the lab condition.

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남중국해 여름몬순과 ENSO와의 가능한 상관관계 (Relationship of South China Sea summer monsoon with ENSO)

  • 최재원;박기준;김정윤;김백조
    • 한국환경과학회지
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    • 제24권6호
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    • pp.827-840
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    • 2015
  • This study analyzed a correlation between South China Sea summer (June to September) monsoon (SCSSM) and the ENSO for the last 32 years (1979 to 2010). There was a correlation that the higher (lower) the SST in the $Ni{\tilde{n}}o-3.4$ region was, the weaker (stronger) the SCSSM intensity was. To identify the reason for this correlation, a difference of means between 8 El $Ni{\tilde{n}}o$ years and 8 La $Ni{\tilde{n}}a$ years (June to September). The analysis on the difference between two groups with respect to the 850 hPa stream flows showed that there were anomalous huge cyclones in the subtropical Pacific in the both hemispheres so that cold and dry anomalous northerlies were strengthened in the South China Sea relatively while anomalous westerlies were strengthened from the Maritime Continent to the off the coast of Chile. The analysis on the difference between two groups with respect to the 200 hPa stream flows showed that the opposite anomalous pressure system pattern to that in the 850 hPa stream flows were shown. In the subtropical Pacific of the both hemispheres, anomalous anticyclones existed so that anomalous easterlies were strengthened from the Maritime Continent to the equatorial central Pacific. Considering the anomalous atmospheric circulations in the upper and lower layers of the troposphere, upward airflows from the equatorial central and eastern Pacific were downward in the South China Sea and the Maritime Continent, which was a structure of anomalous atmospheric circulations. This means that the Walker Circulation was weakened and it was a typical structure of atmospheric circulations revealed in El $Ni{\tilde{n}}o$ years.

젊은 여성의 냉증과 건강지표들의 상관성에 관한 연구 (A Study on the Correlation of Cold Hypersensitivity and Common Health Indexes in Young Women)

  • 최석영;이미주;김은경;이진무;이창훈;장준복;이경섭
    • 대한한방부인과학회지
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    • 제24권4호
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    • pp.62-70
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    • 2011
  • Objectives: The purpose of this study is to investigate the relationship between cold hypersensitivity and common health indexes including dyspepsia, headache, defecation, leucorrhea, and menstruation in young women. Methods: 40 outpatients who visited Kangnam Kyung-Hee Oriental Hospital from January, 2010 to November, 2011 were analyzed. The experimental group consisted of 20 patients diagnosed with cold hypersensitivity, while the control group consisted of 20 patients who were not. All patients were subjected to Digital Infrared Thermal Imaging(DITI), and those with thermal difference greater than $2^{\circ}C$ between anterior thigh and top of feet were diagnosed with cold hypersensitivity. The subjective characteristics of dyspepsia, headache, defecation, leucorrhea, and menstruation were obtained through inquiry by residents at the hospital. The relationship between cold hypersensitivity, dyspepsia, headache, defecation, leucorrhea, and menstruation was analyzed with Independent T-test using SPSS for Windows (version 17.0). Results: Means of defecation, leucorrhea, dysmenorrhea in cold hypersensitivity group were higher than control group without significant statistical difference. Dyspepsia appeared statistically higher in experimental group with significance while headache was the same in both groups. Means of menstrual cycle and menstrual coagulation were higher in non-cold hypersensitivity group, but there was no statistical difference. Conclusions: Results suggest that dyspepsia is common in cold hypersensitivity and treatment of cold hypersensitivity may relieve accompanying digestive problems.

A Study on Comparison of Response Time using Open API of Daishin Securities Co. and eBestInvestment and Securities Co.

  • Ryu, Gui Yeol
    • International journal of advanced smart convergence
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    • 제11권1호
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    • pp.11-18
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    • 2022
  • Securities and investment services have and use large data. Investors started to invest through their own analysis methods. There are 22 major securities and investment companies in Korea and only 6 companies support open API. Python is effective for requesting and receiving, analyzing text data from open API. Daishin Securities Co. is the only open API that officially supports Python, and eBest Investment & Securities Co. unofficially supports Python. There are two important differences between CYBOS plus of Daishin Securities Co. and xingAPI of eBest Investment & Securities Co. First, we must log in to CYBOS plus to access the server of Daishin Securities Co. And the python program does not require a logon. However, to receive data using xingAPI, users log on in an individual Python program. Second, CYBOS plus receives data in a Request/Reply method, and zingAPI receives data through events. It can be thought that these points will show a difference in response time. Response time is important to users who use open APIs. Data were measured from August 5, 2021, to February 3, 2022. For each measurement, 15 repeated measurements were taken to obtain 420 measurements. To increase the accuracy of the study, both APIs were measured alternately under same conditions. A paired t-test was performed to test the hypothesis that the null hypothesis is there was no difference in means. The p-value is 0.2961, we do not reject null hypothesis. Therefore, we can see that there is no significant difference between means. From the boxplot, we can see that the distribution of the response time of eBest is more spread out than that of Cybos, and the position of the center is slightly lower. CYBOS plus has no restrictions on Python programming, but xingAPI has some limits because it indirectly supports Python programming. For example, there is a limit to receiving more than one current price.

중심위와 Myocentric의 재현성 및 상호위치에 관한 연구 (An experimental study on the reproducibility and the position of centric relation and Myocentric)

  • 이종엽;김광남
    • 대한치과보철학회지
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    • 제24권1호
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    • pp.45-54
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    • 1986
  • The establishment and/or registration of an optimal or physiologic relationship between the maxillae and mandible has long been a subject of considerable interest and controversy in dentistry. Centric relation has been generally accepted as a repeatable starting point for restoring the mouth. Recently, it has been claimed that an electronic device (Myo-Monitor) will produce an accurate, reproducible occlusal registration at the vertical and horizontal occlusal position most compatible with the muscular of each patient. The objectives of this study was to compare Myo-Monitor centric to centric relation at the points of reproducibility and anteroposterior, superoinferior position. A Vericheck instrument was employed for examining difference in the position and reproducibility of mandible reproduced by the various check bite records. For this study, 8 dental students and dentists who had no missing teeth and no difficulties of mandibular movement were selected. The following three different positions of the mandible were registered (a) centric relation manipulated by means of chin-point technique with Lucia-jig, (b) centric relation manipulated by means of bilateral technique, (c) Myocentric manipulated by Myo-Monitor. From this experiment, the following results were obtained. 1. Bilateral manipulated centric relation was more reproducible than Myocentric in anteroposterior and superoinferior position , but more reproducible than centric relation manipulated by means of chin point technique with Lucia-jig in anteroposoterior position. Centric relation manipulated by means of chin Point technique with Lucia-jig was more reproducible than Myocentric in right anteroposterior and superoinferior position. 2. Centric relation by means of chin point technique with Lucia-jig was posterior($2.16{\pm}0.78mm$) and superior($0.41{\pm}0.16mm$) to centric occlusion. Bilateral manipulated centric relation was posterior($1.68{\pm}0.10mm$) and superior($1.02{\pm}0.45mm$) to centric occlusion. Myocentric was anterior($0.75{\pm}0.70mm$), inferior($0.59{\pm}0.44mm$) to centric occlusion.

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K-Means Clustering의 차량경로문제 적용연구 (An Application of k-Means Clustering to Vehicle Routing Problems)

  • 하제민;문기주
    • 산업경영시스템학회지
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    • 제38권3호
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    • pp.1-7
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    • 2015
  • This research is to develop a possible process to apply k-means clustering to an efficient vehicle routing process under time varying vehicle moving speeds. Time varying vehicle moving speeds are easy to find in metropolitan area. There is a big difference between the moving time requirements of two specific delivery points. Less delivery times are necessary if a delivery vehicle moves after or before rush hours. Various vehicle moving speeds make the efficient vehicle route search process extremely difficult to find even for near optimum routes due to the changes of required time between delivery points. Delivery area division is designed to simplify this complicated VRPs due to time various vehicle speeds. Certain divided area can be grouped into few adjacent divisions to assume that no vehicle speed change in each division. The vehicle speeds moving between two delivery points within this adjacent division can be assumed to be same. This indicates that it is possible to search optimum routes based upon the distance between two points as regular traveling salesman problems. This makes the complicated search process simple to attack since few local optimum routes can be found and then connects them to make a complete route. A possible method to divide area using k-means clustering is suggested and detailed examples are given with explanations in this paper. It is clear that the results obtained using the suggested process are more reasonable than other methods. The suggested area division process can be used to generate better area division promising improved vehicle route generations.

즉시와 항상적인 관점에서의 U-북디자인 가치 연구 (A Study on the Value of U-Book Design in the Immediate and Ultimate Viewpoints)

  • 김남형
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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    • pp.853-855
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    • 2006
  • 현재 출판계는 'U-출판', 라틴어로는 '유비쿼터스(Ubiquitous)출판' 시대를 맞이하였다. 책의 개념이 전통적인 종이책(paper media book) 개념에서, e-북 개념을 넘어 U-북 개념으로 발전하고 있다. 그러나 시대에 따라 매체에 따라 책의 개념이 바뀌어도 변하는 디자인적 가치와 변하지 않은 디자인적인 가치가 있다. 이러한 관점을 즉시(the immediate)와 항상적(the ultimate)가치라고 할 수 있다. 즉시(the immediate)는 시대정신을 표현하는 현시대의 가치를 의미하고, 항상적인 가치는 디자인을 전달하는 매체의 차이에도 불구하고 시대를 초월하여 변하지 않는 것을 의미한다. 본 연구에서는 2005년부터 시작된 U-북 개념의 디자인을 즉시와 항상적인 가치의 관점에서 연구하고자 한다.

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Influence of inclusion of geosynthetic layer on response of combined footings on stone column reinforced earth beds

  • Maheshwari, Priti;Khatri, Shubha
    • Geomechanics and Engineering
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    • 제4권4호
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    • pp.263-279
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    • 2012
  • The present paper deals with the analysis of combined footings resting on geosynthetic reinforced granular fill overlying stone column improved poor soil. An attempt has been made to study the influence of inclusion of geosynthetic layer on the deflection of the footing. The footing has been idealized as a beam having finite flexural rigidity. Granular fill layer has been represented by Pasternak shear layer and stone columns and poor soil have been represented by nonlinear Winkler springs. Nonlinear behavior of granular fill layer, stone columns and the poor soil has been considered by means of hyperbolic stress strain relationships. Governing differential equations for the soil-foundation system have been derived and solution has been obtained employing finite difference scheme by means of iterative Gauss Elimination method. Results of a detailed parametric study have been presented, for a footing supporting typically five columns, in non-dimensional form in respect of deflection with and without geosynthetic inclusion. Geosynthetic layer has been found to significantly reduce the deflection of the footing which has been quantified by means of parametric study.

An efficient ship detection method for KOMPSAT-5 synthetic aperture radar imagery based on adaptive filtering approach

  • Hwang, JeongIn;Kim, Daeseong;Jung, Hyung-Sup
    • 대한원격탐사학회지
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    • 제33권1호
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    • pp.89-95
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    • 2017
  • Ship detection in synthetic aperture radar(SAR)imagery has long been an active research topic and has many applications. In this paper,we propose an efficient method for detecting ships from SAR imagery using filtering. This method exploits ship masking using a median filter that considers maximum ship sizes and detects ships from the reference image, to which a Non-Local means (NL-means) filter is applied for speckle de-noising and a differential image created from the difference between the reference image and the median filtered image. As the pixels of the ship in the SAR imagery have sufficiently higher values than the surrounding sea, the ship detection process is composed primarily of filtering based on this characteristic. The performance test for this method is validated using KOMPSAT-5 (Korea Multi-Purpose Satellite-5) SAR imagery. According to the accuracy assessment, the overall accuracy of the region that does not include land is 76.79%, and user accuracy is 71.31%. It is demonstrated that the proposed detection method is suitable to detect ships in SAR imagery and enables us to detect ships more easily and efficiently.