• Title/Summary/Keyword: Systematic Correction

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A Study on the Optimal Information Provision for PET-MRI: Focused on Literature Article (PET-MRI에 대한 최적의 정보 제공에 대한 연구: 문헌 보고 중심으로)

  • DongSeob Son;EunHoe Goo
    • Journal of Radiation Industry
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    • v.17 no.4
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    • pp.391-396
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    • 2023
  • Currently, state-of-the-art devices such as SPECT, PET/CT, and PET/MRI are rapidly spreading nationwide, and the penetration rate of nuclear medical devices is also ranked fifth in the world. However, PET/MRI's system is slower and less common because it is more complex than PET/CT. The purpose of this study is to provide optimal information on PET/MRI according to the patient's disease. The subjects obtained information on head and neck cancer, pediatric patients, breast cancer patients, heart disease patients, lung cancer patients, and rectal cancer patients. We tried to accumulate protocols by obtaining a lot of information about each disease. In diagnosing head and neck cancer, it is believed that it is highly likely to be used in evaluating preoperative stage determination, recurrence and remote metastasis after treatment, and unclear primary cervical lymph node metastasis. Diagnosis and continuous follow-up of pediatric patients can increase patient benefits by minimizing radiation exposure. Breast cancer provides a comprehensive evaluation of the clinical need to determine the extent of disease in breast and local lymph nodes and the systematic stages of early diagnosis or recurrence. In diagnosing heart disease patients, MR-based PET motion correction helps to realize the full potential of PET images. For lung cancer patients, the clinical value and usefulness of the resolution and detection ability of integrated PET/MRI for soft tissues such as lung cancer will be sufficient. In diagnosing rectal cancer patients, the detection of missing residual diseases can change the clinical response evaluation for rectal cancer patients treated with TNT, and both the initial stage and treatment response evaluation are possible. Therefore, this literature study provided basic clinical data for PET/MRI tests.

Comparison of High Resolution Image by Ortho Rectification Accuracy and Correlation Each Band (고해상도 영상의 정사보정 정확도 검증 및 밴드별 상관성 비교연구)

  • Jin, Cheong-Gil;Park, So-Young;Kim, Hyung-Seok;Chun, Yong-Sik;Choi, Chul-Uong
    • Journal of Korean Society for Geospatial Information Science
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    • v.18 no.2
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    • pp.35-45
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    • 2010
  • The objective of this study is to verify the positional accuracy by performing the orthometric corrections on the high resolution satellite images and to analyze the band correlation between the high resolution images corrected with orthometric correction. The objectives also included an analysis on the correlation of NDVI. For the orthometric correction of images from KOMPSAT2 and IKONOS, systematic errors were removed in use of RPC data, and non-planar distortions were corrected with GPS surveying data. Also, by preempting the image points at the same positions within ortho images, a comparison was performed on positional accuracies between image points of each image and GPS surveying points. The comparison was also made on the positional accuracies of image points. between the images. For correlation of band and correlation of NDVI, the descriptive statistics of DN values were acquired for respective bands by adding the Quickbird images and Aerial Photographs undergone through orthometric correction at the time of purchase. As result, from a comparison on positional accuracies of Orthoimages from KOMPSAT2 and Ortho Images of IKONOS was made. From the comparison the distance between the image points within each image and GPS surveying points was identified as 3.41m for KOMPSAT2 and as 1.45m for IKONOS, presenting a difference of 1.96m. Whereas, RMSE between image points was identified as 1.88m. The level of correlation was measured by using Quickbird, KOMPSAT2, IKONOS and Aerial Photographs between inter-image bands and NDVI, showing that there were high levels of correlation between Quickbird and IKONOS identified from all bands as well as from NDVI, except a high level of correlation that was identified between the Aerial Photographs and KOMPSAT2 from Band 2. Low levels of correlation were also identified between Quickbird and Aerial Photographs from Band 1. and between KOMPSAT2 and IKONOS from Band 2 and Band 4, whereas, KOMPSAT2 showed low correlations with Aerial Photographs from Band 3. For NDVI, KOMPSAT2 showed low level of correlations with both of QuickBird and IKONOS.

Trace-Back Viterbi Decoder with Sequential State Transition Control (순서적 역방향 상태천이 제어에 의한 역추적 비터비 디코더)

  • 정차근
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.11
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    • pp.51-62
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    • 2003
  • This paper presents a novel survivor memeory management and decoding techniques with sequential backward state transition control in the trace back Viterbi decoder. The Viterbi algorithm is an maximum likelihood decoding scheme to estimate the likelihood of encoder state for channel error detection and correction. This scheme is applied to a broad range of digital communication such as intersymbol interference removing and channel equalization. In order to achieve the area-efficiency VLSI chip design with high throughput in the Viterbi decoder in which recursive operation is implied, more research is required to obtain a simple systematic parallel ACS architecture and surviver memory management. As a method of solution to the problem, this paper addresses a progressive decoding algorithm with sequential backward state transition control in the trace back Viterbi decoder. Compared to the conventional trace back decoding techniques, the required total memory can be greatly reduced in the proposed method. Furthermore, the proposed method can be implemented with a simple pipelined structure with systolic array type architecture. The implementation of the peripheral logic circuit for the control of memory access is not required, and memory access bandwidth can be reduced Therefore, the proposed method has characteristics of high area-efficiency and low power consumption with high throughput. Finally, the examples of decoding results for the received data with channel noise and application result are provided to evaluate the efficiency of the proposed method.

Statistical Issues in the Articles Published in the Journal of Veterinary Clinics (한국임상수의학회지에 발표된 논문의 통계분석 검토)

  • Pak, Son-Il;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.27 no.2
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    • pp.170-174
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    • 2010
  • With the ease availability of statistical software and powerful computers the application of statistical methods in domestic veterinary journals is on the increase. In parallel with this benefit, statistical errors are not uncommon even in renowned scientific and medical journals. These errors may lead to misinterpretation of the data, thereby, subjected to faulty conclusions. A systematic review of articles published in 8 issues of the Journal of Veterinary Clinics during 2006-2007 was performed to assess the statistical methodology and reporting. Ninety-four (72.9%) articles of the 129 original articles screened included any inferential statistical analysis in the article, including comparison of 3 or more groups (53 or 56.4%), comparison of independent 2 groups (40 or 42.6%), and paired t-test (9 or 9.6%) in order. Of the 94 articles in which statistical analysis was done 62 (or 66.0%) had at least 1 statistical error. Errors included failure to apply or incorrectly applying independent Student's t-test for paired data or vice versa, inappropriate use of t-test for more than 3 groups and failure in chi-square test to consider continuity-correction for small expected frequencies. The common errors in ANOVA were failure to validate assumption of the test, inappropriate post-hoc multiple-comparison and incorrect assumption of independence of data in repeated measures design. Reporting errors included failure to state statistical methods and failure to state specific test if more than 1 test was done. It is suggested that an editorial effort would be necessary to achieve the improvement of appropriate statistical procedures through the publication of statistical guidelines to author(s).

STANDARDISATION OF NIR INSTRUMENTS, INFLUENCE OF THE CALIBRATION METHODS AND THE SIZE OF THE CLONING SET

  • Dardenne, Pierre;Cowe, Ian-A.;Berzaghi, Paolo;Flinn, Peter-C.;Lagerholm, Martin;Shenk, John-S.;Westerhaus, Mark-O.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1121-1121
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    • 2001
  • A previous study (Berzaghi et al., 2001) evaluated the performance of 3 calibration methods, modified partial least squares (MPLS), local PLS (LOCAL) and artificial neural networks (ANN) on the prediction of the chemical composition of forages, using a large NIR database. The study used forage samples (n=25,977) from Australia, Europe (Belgium, Germany, Italy and Sweden) and North America (Canada and U.S.A) with reference values for moisture, crude protein and neutral detergent fibre content. The spectra of the samples were collected using 10 different Foss NIR Systems instruments, only some of which had been standardized to one master instrument. The aim of the present study was to evaluate the behaviour of these different calibration methods when predicting the same samples measured on different instruments. Twenty-two sealed samples of different kind of forages were measured in duplicate on seven instruments (one master and six slaves). Three sets of near infrared spectra (1100 to 2500nm) were created. The first set consisted of the spectra in their original form (unstandardized); the second set was created using a single sample standardization (Clone1); the third was created using a multiple sample procedure (Clone6). WinISI software (Infrasoft International Inc., Port Mathilda, PA, USA) was used to perform both types of standardization, Clone1 is just a photometric offset between a “master” instrument and the “slave” instrument. Clone6 modifies both the X-axis through a wavelength adjustment and the Y-axis through a simple regression wavelength by wavelength. The Clone1 procedure used one sample spectrally close to the centre of the population. The six samples used in Clone 6 were selected to cover the range of spectral variation in the sample set. The remaining fifteen samples were used to evaluate the performances of the different models. The predicted values for dry matter, protein and neutral detergent fibre from the master Instrument were considered as “reference Y values” when computing the statistics RMSEP, SEPC, R, Bias, Slope, mean GH (global Mahalanobis distance) and mean NH (neighbourhood Mahalanobis distance) for the 6 slave instruments. From the results we conclude that i) all the calibration techniques gave satisfactory results after standardization. Without standardization the predicted data from the slaves would have required slope and bias correction to produce acceptable statistics. ii) Standardization reduced the errors for all calibration methods and parameters tested, reducing not only systematic biases but also random errors. iii) Standardization removed slope effects that were significantly different from 1.0 in most of the cases. iv) Clone1 and Clone6 gave similar results except for NDF where Clone6 gave better RMSEP values than Clone1. v) GH and NH were reduced by half even with very large data sets including unstandardized spectra.

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Evaluation of Community Health Nursing Practice and Nursing Student's Clinical Experience at Public Health Centers (일개 대학 간호학과생의 보건소 실습평가와 경험에 관한 연구)

  • Park, Jeong-Mo;Lee, Suk-Jeong
    • Research in Community and Public Health Nursing
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    • v.13 no.1
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    • pp.161-170
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    • 2002
  • Purpose: To evaluate community health nursing practice by nursing students for basic data to improve nursing practice education, and to determine the clinical practice experiences of nursing students at public health centers. Method: According to methodological triangulation, all data was collected from March 2001 to June 2001 through prepared questionnaires with 62 Participants, and in depth interviews with 2 Participants, and content analysis with 8 Participants. Results: 1. Clinical practice content was needed to make up professionally. 2. Clinical practice instructor was satisfied with teaching by community health nursing professor, but not by public health center nurse. 3. Clinical environment was perceived as good. 4. Clinical practice time was perceived suitable, but practice evaluation was given a low grade. 5. Experience of nursing students was grouped into 9 categories and 20 themes. 9 Categories are as follows: change of public health center image, difficulty in the personal relationship, positive personal relationships, doubt about the attitude, doubt about the task, tension, worth, ambivalance of the conference, feeling about the end stage of the clinical practice. Twenty themes are stereotypic of the public health care center: recognition, difficulty between tasks and interrelationships with the clients, decrease of self esteem due to deficiency of trust with the students, exchange of feelings in the relationships, the situation of clients was not considered, feelings were disregarded, not systematic, regarding students as supplementory manpower, independent work but not enough contents, anxiety & fear, self-trust, be skilled in the practice, pragmatic knowledge formation, understanding of the old person, self-study of oneself. live up to the expectation, consider as the job, dissolve the stress and impose burden, feeling the lack regarding active approach in the practice. Conclusion: The students have perceived the need of community health nursing through the clinical practice. Clinical practice of community health nursing requires content supplement, correction of instruction by public center nurses, environmental alteration, evaluation criteria set up. Experience of clinical practice in the public health center was as follows: Getting rid of the stereotype about public health center, nursing students comprehended variety and were worth while to do clinical practice in spite of tension& anxiety and fear. And they thought to be a community nurse someday.

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Nutritional Education Status and Recognition of the Importance of Elementary School Dietitians in the Gyeongnam Area (경남지역 초등학교 영양사의 영양교육 실시현황 및 인식조사 - 공동관리 여부와 경력을 중심으로 -)

  • 허은실;양한라;윤현숙;이경혜
    • Korean Journal of Community Nutrition
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    • v.7 no.6
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    • pp.781-793
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    • 2002
  • This study was carried out to investigate the nutritional education status and the recognition of the importance of elementary school dietitians (N=183) in the Gyeongnam area. The results are summarized as follows. All subjects took part in nutritional education program, but the educational methods were passive, as in the case of “home correspondence”(80.8%) and “bulletin board poster”(16.4%), and the education frequency was very low as in “one time/month”(90.2%). The subjects thought “as an independent subject”(41.5%) and “as a related subjects”(35.1%) were suitable teaching venues for the nutritional education. They were very low in individual counseling (4.5%) for school children because of “lack of opportunity”(42.2%) and “heavy work load”(24.1%). However, most of the subjects wished that nutritional counseling could offered in the future (95.5%). The parents' experience of nutritional education was also low (34.3%). Information sources for nutritional education were mainly the “internet”(53.1%) and “re-educational materials” (25.0%). The available instructional materials included “printed materials”(96.7%), “exhibition bulletin materials” (70.3%) and “electronic materials”(46.4%). The preferred education materials were “exhibitionㆍbulletin materials”(32.2%), “printed materials”(29.2%), and “electronic materials”(27.7%). However, materials they wished to purchase were “electronic materials”(54.5%) and “cubic materials”(26.0%). These results show a difference between the preferred materials and the possessed materials. Most school dietitians (98.4%) recognized the necessity of nutritional education with respect to “good table manners”(42.0%), “correction of food prejudices”(30.3%), and “proper nutrition for growth”(21.0%) Although they had a great interest in nutritional education, they had difficulty in cutting their teaming into practice because of “heavy work load”(30.9%), “lack of a systematic curriculum”(25.2%), and “lack of a educational opportunity”(22.8%). Ninety five percent of subjects wished to have nutrition education taught as an independent subject. They pointed out “kindergarten”(60.0%) and “lower grades in elementary school”(33.9%) as the optimal starting times for nutritional education and “school dietitians”(91.3%) as suitable teachers for these programs. The required topics chosen by the subjects for nutritional education for children were “proper eating habits”(54.2%) and “nutritional problem”(31.5%). The dietitians thought “food prejudices”(44.7%), “rat too much processed and instant foods”(36.5%), and “obesity”(11.8%) were the most common nutritional problems among elementary school children. These results suggest the necessity of solving the nutritional problems in children by developing a nutritional education program. Along with this program, if dietitian assisted programs for parents were developed, the effects of nutritional education could definitely be increased.

A Study of Collection Development Policies of the University Libraries in Korea (한국의 종합대학도서관 장서개발정책에 관한 연구)

  • 손정표
    • Journal of Korean Library and Information Science Society
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    • v.11
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    • pp.101-142
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    • 1984
  • This study is a survey of collection development policies in the 40 university libraries among 42 in Korea as of 1984. The survey used a questionnaire with 36 questions concerning the basic elements of the collection development policy. The survey results revealed many problems demanding correction. The measures to correct the problems in the university libraries are as follows. 1. It is desirable that the libraries should have a collection development policy statement written and adopted for the systematic collection building. 2. It is advisable that the libraries should include a function of the materials selection among other various functions of the Library Committee for the purpose of informing administrators of the goals of the libraries and the validity of the budgetary allocation. 3. It is desirable that each library should organize the Collection Development Committee for minimizing the possibility of personal bias on the part of the individual selectors. 4. It is advisable that the primary responsibility for materials selection should be delegated as follows: for the materials for faculty research, to the faculty members; for the other collections, to the professional staff of each department; for the final review of whether or not to purchase, to the Collection Development Committee. 5. It is desirable for the purchase priority of materials to be set up in accordance with the order of 6 levels of collection development. 6. It is advisable that the libraries should, as top priority, purchase materials in direct su n.0, pport of the undergraduate and graduate academic programs, and in subject matter areas other than languages and literature, Korean materials should have not only the higher priority than the foreign language materials, but also maintain the comprehensive collection level. 7. It is desirable that the special collections should be purchased by special funds from the authority, and the special collections librarian should have the responsibility of the materials selection under the advice of the faculty members relating to the subject area. 8. It is advisable that duplicate copies should be bought only for high use items, but for reserve books, by the program enrollment, and textbooks should not be bought in general, except as su n.0, pplemental materials for course work in which they are necessary and heavily used. 9. It is reasonable that the material budget should be distributed as follows: by the ratio for distributing funds, about 60-70% for the library and 30-40% for departments; by the type of materials, about 50% for books, 40% for periodicals and 10% for other materials, or when not bought other materials, about 50-60% for books and 40-50% for periodicals. In addition, it is desirable that undergraduate class enrollment, graduate class enrollment, undergraduate majors, graduate majors, average book cost in the discipline, number of faculty, and use rate by subject should be considered as the factors for the allocation of funds by department, and special consideration should be given to newly-founded departments so the library holdings can be adequate to su n.0, pport them.

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Estimation of Future Design Flood Under Non-Stationarity for Wonpyeongcheon Watershed (비정상성을 고려한 원평천 유역의 미래 설계홍수량 산정)

  • Ryu, Jeong Hoon;Kang, Moon Seong;Park, Jihoon;Jun, Sang Min;Song, Jung Hun;Kim, Kyeung;Lee, Kyeong-Do
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.5
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    • pp.139-152
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    • 2015
  • Along with climate change, it is reported that the scale and frequency of extreme climate events show unstable tendency of increase. Thus, to comprehend the change characteristics of precipitation data, it is needed to consider non-stationary. The main objectives of this study were to estimate future design floods for Wonpyeongcheon watershed based on RCP (Representative Concentration Pathways) scenario. Wonpyeongcheon located in the Keum River watershed was selected as the study area. Historical precipitation data of the past 35 years (1976~2010) were collected from the Jeonju meteorological station. Future precipitation data based on RCP4.5 were also obtained for the period of 2011~2100. Systematic bias between observed and simulated data were corrected using the quantile mapping (QM) method. The parameters for the bias-correction were estimated by non-parametric method. A non-stationary frequency analysis was conducted with moving average method which derives change characteristics of generalized extreme value (GEV) distribution parameters. Design floods for different durations and frequencies were estimated using rational formula. As the result, the GEV parameters (location and scale) showed an upward tendency indicating the increase of quantity and fluctuation of an extreme precipitation in the future. The probable rainfall and design flood based on non-stationarity showed higher values than those of stationarity assumption by 1.2%~54.9% and 3.6%~54.9%, respectively, thus empathizing the necessity of non-stationary frequency analysis. The study findings are expected to be used as a basis to analyze the impacts of climate change and to reconsider the future design criteria of Wonpyeongcheon watershed.

Estimation of reflectivity-rainfall relationship parameters and uncertainty assessment for high resolution rainfall information (고해상도 강수정보 생산을 위한 레이더 반사도-강수량 관계식 매개변수 보정 및 불확실성 평가)

  • Kim, Tae-Jeong;Kim, Jang-Gyeong;Kim, Jin-Guk;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.54 no.5
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    • pp.321-334
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    • 2021
  • A fixed reflectivity-rainfall relationship approach, such as the Marshall-Palmer relationship, for an entire year and different seasons, can be problematic in cases where the relationship varies spatially and temporally throughout a region. From this perspective, this study explores the use of long-term radar reflectivity for South Korea to obtain a nationwide calibrated Z-R relationship and the associated uncertainties within a Bayesian inference framework. A calibrated spatially structured pattern in the parameters exists, particularly for the wet season and parameter for the dry season. A pronounced region of high values during the wet and dry seasons may be partially associated with storm movements in that season. Overall, the radar rainfall fields based on the proposed modeling procedure are similar to the observed rainfall fields. In contrast, the radar rainfall fields obtained from the existing Marshall-Palmer relationship show a systematic underestimation. In the event of high impact weather, it is expected that the value of national radar resources can be improved by establishing an active watershed-level hydrological analysis system.