• Title/Summary/Keyword: statistical process control

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The Effect of Forward Head Posture Correctional Device During Computer Work (컴퓨터 작업 시 전방머리자세 교정장치의 효과)

  • Yi, Chung-Hwi;Yoo, Won-Gyu;Kim, Min-Hee
    • Physical Therapy Korea
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    • v.13 no.1
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    • pp.9-15
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    • 2006
  • Work-related musculoskeletal disorder has been associated with long hours of computer work and prolonged periods of static posture. In clinical settings, postural correction is a common treatment approach for individuals with neck, shoulder, and back pain. This study was designed to identify the effect of Forward Head Posture Correctional Device during computer work. Twelve healthy adults (mean age, 27.4 yrs; mean height, 165.0cm mean weight, 65.8 kg) participated in the study. They had no medical history of neurological or surgical problems with their upper extremity. The subjects were asked to perform Head Forward Posture under the guidance of physical therapists and the measured angles were analyzed using a 3-D motion analysis system. Markers were placed on the C7 spinous process, tragus of the ear and forward head angle was between the line from the tragus to the C7 line and the Y-axis at the C7. The statistical significance of difference between, "without" and "with" correctional device was tested by paired t-test. A level of significance was set at ${\alpha}$=.05. In comparison of the computer work between "without" and "with" correctional device, Forward Head Angle was showed significant difference (p<.05). In conclusion, the range of Forward Head Angle was significantly decreased during computer work with the correctional device. Further research is needed to understand the nature of motor control problems in deep muscles in patients with neck, shoulder, and back pain.

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A Study on The Correction of The Channel Equalizer Decision Error Using Channel Estimator (채널추정기를 이용한 등화기 결정오류 정정 알고리즘에 관한 연구)

  • Kim, Seon-Woong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.8
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    • pp.18-24
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    • 2017
  • The process of transmitting messages through a medium with a limited bandwidth or channel dispersion inevitably involves signal distortion and noise influxes, resulting in the degradation of transmission quality due to the inter-symbol interference and additional noise, which increases the error rate of the received symbols. The main role of the equalizer is to remove the channel distortion and noise from the received signal to recover the transmitted messages. A number of studies on the equalizer composed of a combination of linear filter and error control coding have shown that they played a key role in enhancing the transmission efficiency, which is essential for digital communication. This paper proposes a new algorithm to correct the residual symbol errors in the message signal. In general, equalizer performance improvement algorithms were developed to improve the initial convergence speed or steady-state error. In this paper, however, the equalizer input signal was reconstructed using the equalizer decision symbols and the channel estimates to directly correct the decision errors by analyzing the statistical characteristics of the difference signal between the actual received signal and the reconstructed signal.

Application of MARSSIM for Final Status Survey of the Decommissioning Project (해체사업의 최종현황조사를 위한 MARSSIM 적용)

  • Hong, Sang-Bum;Lee, Ki-Won;Park, Jin-Ho;Chung, Un-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.9 no.2
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    • pp.107-111
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    • 2011
  • The release of a site and building from regulatory control is the final stage of the decommissioning process. The MARSSIM (Multi-Agency Radiation Survey and Site Investigation Manual) provides overall framework for conducting data collection for a final status survey to demonstrate compliance with site closure requirements. The KAERI carried out establishing a final status survey by using the guidance provided in the MARSSIM for of a site and building of the Korea Research Reactor. The release criteria for a site and building were set up based on these results of the site specific release levels which were calculated by using RESRAD and RESRAD-Build codes. The survey design for a site and building was classified by using the survey dataset and potential contamination. The number of samples in each survey unit was calculated by through a statistical test using the collected data from a scoping and characterization survey. The results of the final status survey were satisfied the release criteria based on an evaluation of the measured data.

Improving Research Information Security in Academic Institutes through the Analysis of Security Awareness and Activities (보안 인지 및 실천 현황 분석을 통한 대학 연구정보보안 수준 제고 방안)

  • Park, Il-Hyung;Kim, Seong-Woo;Seo, Seung-Woo
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.20 no.2
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    • pp.91-108
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    • 2010
  • Universities are one of leading R&D institutes, however, their scarce security investment allows research information to leak outside. This paper proposes methods for improving security level of academic institutes to protect research information by analyzing security awareness and activities. To do that, we verified the current status of information security and awareness level by analyzing the survey which was conducted for a member of Seoul National University. As a result of statistical analysis using correlation, analysis of variance, multi regression and so on, we concluded that it is essential to improve security awareness, activities, professor's security level and management process for research labs. Thus, we suggest the following methods, security awareness and knowledge development through education, security management for research labs through provision, introduction of data protection softwares and physical control of visitors which are to be adopted to improve security level.

Does the palatal vault form have an influence on the scan time and accuracy of intraoral scans of completely edentulous arches? An in-vitro study

  • Osman, Reham;Alharbi, Nawal
    • The Journal of Advanced Prosthodontics
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    • v.14 no.5
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    • pp.294-304
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    • 2022
  • PURPOSE. The purpose of this study was to evaluate the influence of different palatal vault configurations on the accuracy and scan speed of intraoral scans (IO) of completely edentulous arches. MATERIALS AND METHODS. Three different virtual models of a completely edentulous maxillary arch with different palatal vault heights- Cl I moderate (U-shaped), Cl II deep (steep) and Cl III shallow (flat)-were digitally designed using CAD software (Meshmixer; Autodesk, USA) and 3D-printed using SLA-based 3D-printer (XFAB; DWS, Italy) (n = 30; 10 specimens per group). Each model was scanned using intraoral scanner (Trios 3; 3ShapeTM, Denmark). Scanning time was recorded for all samples. Scanning accuracy (trueness and precision) were evaluated using digital subtraction technique using Geomagic Control X v2020 (Geomagic; 3DSystems, USA). One-way analysis of variance (ANOVA) test was used to detect differences in scanning time, trueness and precision among the test groups. Statistical significance was set at α = .05. RESULTS. The scan process could not be completed for Class II group and manufacturer's recommended technique had to be modified. ANOVA revealed no statistically significant difference in trueness and precision values among the test groups (P=.959 and P=.658, respectively). Deep palatal vault (Cl II) showed significantly longer scan time compared to Cl I and III. CONCLUSION. The selection of scan protocol in complex cases such as deep palatal vault is of utmost importance. The modified, adopted longer path scan protocol of deep vault cases resulted in increased scan time when compared to the other two groups.

A Systems Engineering Approach for Predicting NPP Response under Steam Generator Tube Rupture Conditions using Machine Learning

  • Tran Canh Hai, Nguyen;Aya, Diab
    • Journal of the Korean Society of Systems Engineering
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    • v.18 no.2
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    • pp.94-107
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    • 2022
  • Accidents prevention and mitigation is the highest priority of nuclear power plant (NPP) operation, particularly in the aftermath of the Fukushima Daiichi accident, which has reignited public anxieties and skepticism regarding nuclear energy usage. To deal with accident scenarios more effectively, operators must have ample and precise information about key safety parameters as well as their future trajectories. This work investigates the potential of machine learning in forecasting NPP response in real-time to provide an additional validation method and help reduce human error, especially in accident situations where operators are under a lot of stress. First, a base-case SGTR simulation is carried out by the best-estimate code RELAP5/MOD3.4 to confirm the validity of the model against results reported in the APR1400 Design Control Document (DCD). Then, uncertainty quantification is performed by coupling RELAP5/MOD3.4 and the statistical tool DAKOTA to generate a large enough dataset for the construction and training of neural-based machine learning (ML) models, namely LSTM, GRU, and hybrid CNN-LSTM. Finally, the accuracy and reliability of these models in forecasting system response are tested by their performance on fresh data. To facilitate and oversee the process of developing the ML models, a Systems Engineering (SE) methodology is used to ensure that the work is consistently in line with the originating mission statement and that the findings obtained at each subsequent phase are valid.

SWOT Analysis and Expert Assessment of the Effectiveness of the Introduction of Healthcare Information Systems in Polyclinics in Aktobe, Kazakhstan

  • Lyudmila, Yermukhanova;Zhanar, Buribayeva;Indira, Abdikadirova;Anar, Tursynbekova;Meruyert, Kurganbekova
    • Journal of Preventive Medicine and Public Health
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    • v.55 no.6
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    • pp.539-548
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    • 2022
  • Objectives: The purpose of this study was to assess the organizational effectiveness of the introduction of a healthcare information system (electronic medical records and databases) in healthcare in Kazakhstan. Methods: The authors used a combination of 2 methods: expert assessment and strengths, weaknesses, opportunities, and threats (SWOT) analysis. SWOT analysis is a necessary element of research, constituting a mandatory preliminary stage both when drawing up strategic plans and for taking corrective measures in the future. The expert survey was conducted using 2 questionnaires. Results: The study involved 40 experts drawn from specialists in primary healthcare in Aktobe: 15 representatives of administrative and managerial personnel (chief doctors and their deputies, heads of medical statistics offices, organizational and methodological offices, and internal audit services) and 25 general practitioners. Conclusions: The following functional indicators of the medical and organizational effectiveness of the introduction of information systems in polyclinics were highlighted: first, improvement of administrative control, followed in descending order by registration and movement of medical documentation, statistical reporting and process results, and the cost of employees' working time. There has been no reduction in financial costs, namely in terms of the costs of copying, delivery of information in paper form, technical equipment, and paper.

The Effects of Ascorbic Acid on Full-thickness Skin Wound Healing in Dogs (개에서 Ascorbic Acid가 피부 결손창 치유에 미치는 영향)

  • Kim Jung Hun;Cheong Jongtae;Park Hyun Jeong;Kim Jae Hoon;Lee Kyoung-kap;Son Won-geun;Kang Tae-young;Yun Young-min;Hwang Kyu-kye;Park Jong-Cook;Lee Joo Myoung
    • Journal of Veterinary Clinics
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    • v.22 no.4
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    • pp.342-347
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    • 2005
  • This study was designed to assess the healing effects of ascorbic acid on full-thickness skin wound in dogs. Four $2.5\pm2.5cm$ full-thickness skin wounds were created bilaterally on the dorsolateral aspect in each of 5 dogs. The ten wounds were treated with ascorbic acid solution in the experimental group, and the ten wounds were treated with $0.9\%$ saline in the control group. The wound healing area was measured every other day for 3 weeks after the wounding. Statistical analysis was conducted with the paired t-test. On the $1^{st},\;3^{rd},\;5^{th},\; 7^{th},\;9^{th},\;11^{th},\;13^{th},\;15^{th},\;17^{th},\;19^{th},\;21^{st}days$, the wound healing rates were $12.6\pm9.6\%,\;9.5\pm9.8\%,\;18.9\pm9.0\%,\;39.2\pm5.4\%,\;62.2\pm4.6\%,\;86.9\pm1.9\%,\;92.9\pm1.8\%,\;96.6\pm1.6\%,\;99.1\pm0.5\%,\;99.8\pm0.2\%,\;99.9\pm0.1\%$ in the experimental group, and $9.1\pm6.0\%,\;9.2\pm6.0\%,\;12.2\pm5.0\%,\;41.3 \pm6.3\%,\;54.2\pm9.2\%,\;81.0\pm2.6\%,\;85.7\pm2.8\%,\;92.3\pm1.5\%,\;96.1\pm0.7\%,\;98.0\pm0.8\%,\;99.5\pm0.2\%$ in the control group On the $15^{th}$ day, the wound closed above $99\%$ in 2 dogs of the experimental group. On the $17^{th}$ day, the wound closed above $99\%$ in 3 dogs of the experimental group. On the $19^{th}$ day, the wound closed above $99\%$ in 5 dogs of the experimental group, and 2 dogs of the control group. On the $21^{st}$ day, the wound closed above $99\%$ in 5 dogs of the experimental group, and 4 dogs of the control group. The wound healing rate of the experimental group was $2\~4$ days faster than that of the control group. The tensile strength was $4,169\pm1,107g/cm^2$ in the experimental group, and $2,438\pm637g/cm^2$ in the countrol group on the$21^{st}$ day after wounding. Tensile strength was significantly higher in the experimental group than in the control group (p<0.05). The histopathological findings of the experimental group were similar to those of the control group on the $1^{st},\;3^{rd}\;and\;5^{th}$days. Inflammation and revascularization of the experimental group were similar to those of the control group on the $9^{th},\;13^{th}\;and\;21^{st}$days. The formation of collagen and reepithelialization were more developed the experimental group than in the control group on the $9^{th},\;13^{th}\;and\;21^{st}$days. Significantly higher wound healing rate, tensile strength and better histopathological findings were observed in the experimental group than in the control group. These results suggest that the topical application of ascorbic acid on full-thickness skin wounds can promote wound healing process.

Impact of Transformational Leadership and Internal Marketing on Management Performance with the Mediation of Job Satisfaction and Customer Orientation: Focus on Clothing Store Managers (변혁적 리더십, 내부마케팅이 구성원들의 직무만족, 고객지향성을 매개로 경영성과에 미치는 영향: 의류매장 관리자를 중심으로)

  • Choi, Jeong-Hee;Park, Woojin;Bae, byung Yun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.3
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    • pp.89-101
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    • 2020
  • The purpose of this study is to examine how the variables of managerial competencies, namely transformational leadership, internal marketing, and structural influences, affect managerial performance through job satisfaction and customer orientation, by focusing on managers of clothing stores. Furthermore, the study aims to draw implications in connection with academic or practical start-ups that can improve management performance. Through examples of transformational leadership, internal marketing, and management performance of the previous study, the significance of the study is further stressed. Also, based on the previous study, this study empirically analyzes what results can be expected, focusing on managers of retail clothing stores, department stores, franchise stores, etc. In this study, we conduct an empirical analysis of 305 managers of retail clothing stores, department stores, franchise stores, etc. Because the results of the empirical analysis are from experiments at clothing stores first, it is found that managers' transformational leadership must go through a mediating effect process, which is job satisfaction for management performance. Second, it is found that transformational leadership must also go through a mediating effect process, which is customer orientation for management performance. Third, it is found that internal marketing must also go through a mediating effect process, which is job satisfaction for management performance. Therefore, as the researcher sought to verify, there is a complete mediating effect in retail clothing stores, department stores, franchise stores, etc., and it is confirmed that its role is significant. A study on whether or not entrepreneurship, as a control variable, affects business performance is conducted to find the statistical values that can be determine management performance when managers of retail clothing stores, department stores, and franchise stores answer entrepreneurial surveys with education- and knowledge-intensive backgrounds. As a result, with the statistical figures, it is confirmed that the managers are striving to improve their management performance based on their education- and knowledge-intensive backgrounds. Based on the research results, this study tried to test the parameters that can improve the management performance through empirical analysis centering on managers, Furthermore, the study attempted to draw implications for academic, practical, and start-ups that can improve management performance.

Effect of abutment superimposition process of dental model scanner on final virtual model (치과용 모형 스캐너의 지대치 중첩 과정이 최종 가상 모형에 미치는 영향)

  • Yu, Beom-Young;Son, Keunbada;Lee, Kyu-Bok
    • The Journal of Korean Academy of Prosthodontics
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    • v.57 no.3
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    • pp.203-210
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    • 2019
  • Purpose: The purpose of this study was to verify the effect of the abutment superimposition process on the final virtual model in the scanning process of single and 3-units bridge model using a dental model scanner. Materials and methods: A gypsum model for single and 3-unit bridges was manufactured for evaluating. And working casts with removable dies were made using Pindex system. A dental model scanner (3Shape E1 scanner) was used to obtain CAD reference model (CRM) and CAD test model (CTM). The CRM was scanned without removing after dividing the abutments in the working cast. Then, CTM was scanned with separated from the divided abutments and superimposed on the CRM (n=20). Finally, three-dimensional analysis software (Geomagic control X) was used to analyze the root mean square (RMS) and Mann-Whitney U test was used for statistical analysis (${\alpha}=.05$). Results: The RMS mean abutment for single full crown preparation was $10.93{\mu}m$ and the RMS average abutment for 3 unit bridge preparation was $6.9{\mu}m$. The RMS mean of the two groups showed statistically significant differences (P<.001). In addition, errors of positive and negative of two groups averaged $9.83{\mu}m$, $-6.79{\mu}m$ and 3-units bridge abutment $6.22{\mu}m$, $-3.3{\mu}m$, respectively. The mean values of the errors of positive and negative of two groups were all statistically significantly lower in 3-unit bridge abutments (P<.001). Conclusion: Although the number of abutments increased during the scan process of the working cast with removable dies, the error due to the superimposition of abutments did not increase. There was also a significantly higher error in single abutments, but within the range of clinically acceptable scan accuracy.