• Title/Summary/Keyword: accuracy-study

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A Study on Accuracy Analysis of DGPS-Based Marine Radiobeacon in the East Coast of Korea (한국동해안에서의 Marine Radiobeacon/DGPS 정밀도 분석에 관한 연구)

  • 고광섭;이형욱;정세모
    • Journal of the Korean Institute of Navigation
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    • v.22 no.1
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    • pp.1-13
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    • 1998
  • Radiobeacons that carry corrections for global satellite navigation systems are currently being planned or installed in many countries. In early 1996, it was begun to send DGPS correction message from a marine radiobeacon station located in Changgi Got Lighthouse. It was the first test broadcast of DGPS correction data based on medium frequency of marine radiobeacon where transmission power and rate are 300W and 100bps respectively in Korea. However, there has not been any scientific study on the characteristic of the accuracy of a marine radiobeacon/DGPS. Accordingly, this paper investigates the accuracy of the system, which is currently operating in 310kHz. To do this , the real time differential correction in RTCM data was collected in an implemented system. And then the accuracy was analyzed related to the coverge of the radiobeacon/DGPS. As a result, it is verified that the differential positioning accuracy using the marine radiobeacon is sufficient to ensure the safety of marine activities around the coast of Korea.

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A Study on Roughness Characteristic about Rotational Accuracy Variation (스핀들의 회전 정밀도에 따른 표면 거칠기 특성 연구)

  • Park, Ki-Beom;Chung, Won-Jee;Lee, Choon-Man
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.1
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    • pp.110-115
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    • 2009
  • In general, the radial error motion of a machine tool spindle system is effected on the accuracy of the parts to be made. This paper presents in milling process an investigation into spindle rotational accuracy effects on surface roughness of processing parts. We experimented the effects on spindle rotational accuracy in milling process by cutting AL 7075 workpiece at various rotational speed. In order to analyze the effects of rotational accuracy on surface roughness, we proposed the method using iSIGHT's RBF Approximation. The proposed method can be used fur anticipating the surface roughness when some spindle rotational accuracy experiments could be done in milling process.

The Effect of Education Program on Primiparas로 Knowledge, Confidence and Accuracy of Behavior in Newborn Care (신생아 돌보기 교육 프로그램이 초산모의 신생아 돌보기 지식, 자신감, 행동 정확도에 미치는 효과)

  • 서영미
    • Journal of Korean Academy of Nursing
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    • v.28 no.4
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    • pp.1060-1074
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    • 1998
  • This study was to find whether the educational program contributed to the increase of knowledge, confidence, and accuracy of behavior in newborn care of the primiparas. The educational program consistes of individual lectures, demostrations, discussion, and practice of newborn care. Also two telephone counseling with the subjects after they are discharged from hospital. This study is a quasi-experimental design using non-equivalent control group pretest-posttest design. Data collection was done from July 21 to Oct 4 in 1997. The subjects were selected from 2 general hospitals and 1 university hosipital in C city, Subjects were 44 primiparas(control group 22, experimental group 22). they were tested on knowledge, confidence, and accuracy of behavior in newborn care. A pretest was done 2-3 days after vaginal delivary(5-6 days after c-sec delivary). A posttest was done 21-28 day(vaginal delivary, c-sec delivary) after delivary. The instruments used for this study were knowledge scale about newbon care developed by the reserarcher, Pharis' confidence scale modified by the researcher and accuracy of behavior scale developed by the reserarcher. Primiparas' knowledge and confidence was tested by questionnaire and Primiparas' accuracy of behavior was tested by structured observational method. Analysis of data was done by using of χ²- test, t -test, paired t -test. The results of this study are summarized as follows : 1) Knowledge of the experimental group was significant higher than the control group(t=-4.94, P=.000). 2) Confidence of the experimental group was significant higher than the control group(t=-.262, P=.012). 3) Accuracy of behavior of the experimental group was significant higher than the control group (t=-.969, P=.000). In conclusion, the newborn care education along with intensive telephon counseling shows a significant promotion of newbon care in primiparas. Thus this program can be recommended as an intervention model for the newborn and primiparas.

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Reliability of a chairside CAD-CAM surgical guide for dental implant surgery on the anterior maxilla: An in vitro study

  • Phyo Ei Ei Htay;Richard Leesungbok;Suk Won Lee;Yu-Jin Jee;Kyung Lhi Kang;Sung Ok Hong
    • The Journal of Advanced Prosthodontics
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    • v.15 no.5
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    • pp.259-270
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    • 2023
  • PURPOSE. This study evaluated the reliability of the chair-side CAD-CAM surgical guide (CSG) in the anterior maxilla by comparing its accuracy with the laboratory 3D-printed surgical guide (3DSG) and manual surgical guide (MSG) concerning different levels of dentists' surgical experience. MATERIALS AND METHODS. Ten surgical guides of each type (MSG, 3DSG, and CSG) were fabricated on a control study model with missing right and left central incisors. Sixty implants were placed in 30 study models by two dentists (one inexperienced and one experienced) using three different types of surgical guides. Horizontal deviations at shoulder and at apex, vertical, and angular deviations were measured after superimposing the planned and placed implant positions in the software. Kruskal-Wallis and Mann-Whitney U tests were used to compare the accuracy of three types of surgical guides in each dentist group and the accuracy of each surgical guide between two dentists (α = .05). RESULTS. There were no significant differences in any deviations between CSG and 3DSG, apart from angular deviation, for both dentists' groups. Moreover, both CSG and 3DSG showed no significant differences in accuracy between the two dentists (P > .05). In contrast, MSG demonstrated significant differences from CSG and 3DSG and a significant difference in accuracy between the two dentists (P < .05). CONCLUSION. CSG provides superior accuracy to MSG in implant placement in the maxillary anterior region and is comparable to 3DSG at different levels of surgical experience, while offering the benefits of shorter manufacturing time and reduced patient visits.

Accuracy, Sensitivity and Specificity of Fine Needle Aspiration Biopsy for Salivary Gland Tumors: A Retrospective Study from 2006 to 2011

  • Silva, William P P;Stramandinoli-Zanicotti, Roberta T;Schussel, Juliana L;Ramos, Gyl H A;Ioshi, Sergio O;Sassi, Laurindo M
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.4973-4976
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    • 2016
  • Objective: This article concerns evaluation of the sensitivity, specificity and accuracy of FNAB for pre-surgical diagnosis of benign and malignant lesions of major and minor salivary glands of patients treated in the Department of Head and Neck Surgery of Erasto Gartner Hospital. Methods: This retrospective study analyzed medical records from January 2006 to December 2011 from patients with salivary gland lesions who underwent preoperative FNAB and, after surgical excision of the lesion, histopathological examination. Results: The study had a cohort of 130 cases, but 34 cases (26.2%) were considered unsatisfactory regarding cytology analyses. Based on the data, sensitivity was 66.7% (6/9), specificity was 81.6% (71/87), accuracy was 80.2% (77/96), the positive predictive value was 66,7% (6/9) and the negative predictive value was 81.6% (71/87). Conclusion: Despite the high rate of inadequate samples obtained in the FNAB in this study the technique offers high specificity, accuracy and acceptable sensitivity.

A Study on Improvement of Finishing Accuracy Using 3-Axis Machine for Curved Surface Dies (3축 가공기를 이용한 곡면 금형의 연마 정밀도 향상에 관한 연구)

  • Lim, Dong-Jae;Lee, Sang-Jik;Jeong, Hae-Do
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.3
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    • pp.61-67
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    • 2001
  • The finishing process for die is an important process because it has influence on final quality of products. Recently s study on development of 5-axis die automated finishing machine has been progressed. But die must be moved from the cutting machine to the die automated finishing machine. So manufacturing cost and time increase and machining error occurs by transfer. So, in this study, a 3-axis machining center was applied to die finishing. Because cutting tool can be changed to finishing tool by ATC, both of cutting and finishing process are possible on the machine. However, this application results in the decrease of finishing for the improvement of form accuracy. So this study focused on the generation of finishing tool path suitable to 3-axis die finishing for the improvement of form accuracy. The form accuracy evaluation is performed by the measurement of removal depth using a stylus profilometer. From the result, it is confirmed that form accuracy was improved less than 2$\mu$m of removal depth error.

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A study on the Effective Use of Environmental Information System in Korea - focused on the accuracy of raw data - (환경정보체계 구축의 효과적 이용 - 원자료의 정확성을 중심으로 -)

  • 이규석
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 1998.11a
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    • pp.34-36
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    • 1998
  • In Korea, the initial installation of GIS requires lots of cost, time, and human efforts, If the accuracy of GIS data does not meet the certain standard for use, the system may not work as expected. So, it needs to be investigated for the accuracy of raw data. However, there is little study for the accuracy of raw data in Korea. Therefore, the purpose of this study is to review the data accuracy of raw data - geologic map, 1:5,000 and 1:25,000 scale topographic map, forest stand map, degree of green naturality(DGN) map, and detailed survey data of DGN map - for fulfilling the expected use in Korea. After this study, some errors in data were surveyed and following conclusions were derived. (1) There is a lack of data, e. g, wildlife habitat map. (2) Some data are misinterpreted depending on the location in the geologic map. (3) Some data are not updated after change of topography in the topographic map. (4) Some data are not edited properly in the forest stand map. (4) DGN classification system does not reflect the characteristic of Korean vegetation community. So, it needs to be refined and restructured.

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Earnings Attributes that Contribute to Analyst Forecasting Errors: Empirical Evidence from Korea

  • KIM, Joonhyun
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.8
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    • pp.647-658
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    • 2021
  • Analysts' forecasts are important for providing useful guidance to investors, especially individual or small investors, and therefore it becomes critical to identify the elements which can potentially increase errors in analysts' forecasts. This study investigates potential factors which can lead to errors in forecasting by analysts, specifically in terms of the level and attributes of corporate earnings. Utilizing a sample of firms listed on the Korean stock markets, this study provides evidence that firms with more volatile and unpredictable earnings feature less accurate analyst forecasts. This study fills a void in the literature by conducting empirical tests for earnings attributes in terms of volatility and unpredictability that could potentially undermine the forecast accuracy. The negative association between the quality of earnings and forecast accuracy is more pronounced for firms with negative net income values. Additional analysis demonstrates that forecast accuracy is significantly lower for the fourth quarter than for other fiscal quarters and that fourth quarter earnings tend to be more volatile and unpredictable. This study contributes to the literature by providing new empirical evidence regarding the comprehensive effects of earnings quality and level on analysts' forecasting accuracy and further suggests potential factors contributing to the fourth quarter anomaly in analyst forecasts in terms of earnings attributes.

Effects of Auricular Acupressure on the Accuracy of Breaking and Competitive State Anxiety in Taekwondo Players (귀지압이 태권도선수의 격파 정확성 및 경쟁상태불안에 미치는 영향)

  • Kim, Ji Won;Lee, Eun Jin;Noh, Jeong Hwan
    • Journal of muscle and joint health
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    • v.29 no.2
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    • pp.133-140
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    • 2022
  • Purpose: This study was to examine the effects of auricular acupressure on competitive state anxiety and the accuracy of breaking in taekwondo players. Methods: This study was a quasi-experimental study with a time-series design. Twenty-two taekwondo breaking players were assigned to the control group for the first two weeks and then assigned to the experimental group for the next two weeks. Anxiety was measured by the revised Competitive State Anxiety Inventory-2 and the accuracy of breaking was measured as a percentage of breaking the wooden board. Results: Auricular acupressure for two weeks significantly increased the accuracy of breaking from 80.83±7.99% to 90.92±7.57% (t=7.74, p<.001). Auricular acupressure for two weeks significantly increased anxiety from 35.66±10.36 to 50.64±7.45 (t=4.38, p<.001). Among three subtypes of competitive state anxiety, somatic anxiety was increased from 12.48±4.97 to 22.95±4.54 (t=2.09, p=.011). Cognitive anxiety was significantly increased from 10.11±3.96 to 14.68±3.89 (t=5.37, p<.001) but self-confidence was not changed. Conclusion: The results of this study showed that auricular acupressure was effective in increasing the accuracy of breaking in taekwondo players.

Genetic evaluation and accuracy analysis of commercial Hanwoo population using genomic data

  • Gwang Hyeon Lee;Yeon Hwa Lee;Hong Sik Kong
    • Journal of Animal Reproduction and Biotechnology
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    • v.38 no.1
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    • pp.32-37
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    • 2023
  • This study has evaluated the genomic estimated breeding value (GEBV) of the commercial Hanwoo population using the genomic best linear unbiased prediction (GBLUP) method and genomic information. Furthermore, it analyzed the accuracy and realized accuracy of the GEBV. 1,740 heads of the Hanwoo population which were analyzed using a single nucleotide polymorphism (SNP) Chip has selected as the test population. For carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS), the mean GEBVs estimated using the GBLUP method were 3.819, 0.740, -0.248, and 0.041, respectively and the accuracy of each trait was 0.743, 0.728, 0.737, and 0.765, respectively. The accuracy of the breeding value was affected by heritability. The accuracy was estimated to be low in EMA with low heritability and high in MS with high heritability. Realized accuracy values of 0.522, 0.404, 0.444, and 0.539 for CWT, EMA, BFT, and MS, respectively, showing the same pattern as the accuracy value. The results of this study suggest that the breeding value of each individual can be estimated with higher accuracy by estimating the GEBV using the genomic information of 18,499 reference populations. If this method is used and applied to individual selection in a commercial Hanwoo population, more precise and economical individual selection is possible. In addition, continuous verification of the GBLUP model and establishment of a reference population suitable for commercial Hanwoo populations in Korea will enable a more accurate evaluation of individuals.