• Title/Summary/Keyword: Stability Rating Test

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Estimation of the excavation damage zone in TBM tunnel using large deformation FE analysis

  • Kim, Dohyun;Jeong, Sangseom
    • Geomechanics and Engineering
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    • v.24 no.4
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    • pp.323-335
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    • 2021
  • This paper aims to estimate the range of the excavation damaged zone (EDZ) formation caused by the tunnel boring machine (TBM) advancement through dynamic three-dimensional large deformation finite element analysis. Large deformation analysis based on Coupled Eulerian-Lagrangian (CEL) analysis is used to accurately simulate the behavior during TBM excavation. The analysis model is verified based on numerous test results reported in the literature. The range of the formed EDZ will be suggested as a boundary under various conditions - different tunnel diameter, tunnel depth, and rock type. Moreover, evaluation of the integrity of the tunnel structure during excavation has been carried out. Based on the numerical results, the apparent boundary of the EDZ is shown to within the range of 0.7D (D: tunnel diameter) around the excavation surface. Through series of numerical computation, it is clear that for the rock of with higher rock mass rating (RMR) grade (close to 1st grade), the EDZ around the tunnel tends to increase. The size of the EDZ is found to be direct proportional to the tunnel diameter, whereas the depth of the tunnel is inversely proportional to the magnitude of the EDZ. However, the relationship between the formation of the EDZ and the stability of the tunnel was not found to be consistent. In case where the TBM excavation is carried out in hard rock or rock under high confinement (excavation under greater depth), large range of the EDZ may be formed, but less strain occurs along the excavation surface during excavation and is found to be more stable.

Design of a Multi-Protocol Gateway System Based on Low Power Wireless Communications (저전력 무선통신 기반 다중 프로토콜 게이트웨이 시스템 설계)

  • Hong, Sung-IL;Lin, Chi-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.10
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    • pp.2006-2013
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    • 2015
  • In this paper we propose a multi-protocol gateway system based on low power wireless communications. The proposed multi-protocol gateway system was designed to allow real-time monitoring and control of the on-site situation through wired and wireless networks by gathering information for streetlight power control and environmental monitoring. The sensing data using multi-sensors with composite processing that selectively used wired or wireless communication (e.g., CDMA, Ethernet (TCP/IP), GPS, etc.) were designed to act as intermediaries that transmitted to the main server through ZigBee. Inaddition, they were designed by separating a CPU board and baseboard to ensure low maintenance cost and ease of hardware replacement. The proposed multi-protocol gateway system's power, impact, continuous operation stability, and immunity test results obtained a normal operation success rate of over 95% and normal continuous operation results. Moreover, in the voltage drop test, instantaneous immunity test, and conductive RF electromagnetic field immunity test, it obtained an average rating result of "A".

Quality Evaluation on Use of Camellia Oil as an Alternative Method in Dried Seaweed Preparation

  • Kim, Jae Kyeom;Park, Hui Gyu;Kim, Cho Rong;Lim, Ho-Jeong;Cho, Kye Man;Choi, Jine Shang;Shin, Dong-Hoon;Shin, Eui-Cheol
    • Preventive Nutrition and Food Science
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    • v.19 no.3
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    • pp.234-241
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    • 2014
  • The fatty acid and volatile compound compositions of camellia oil were analyzed in this study. The impacts of the replacement of conventional vegetable oil with camellia oil on the sensory attributes of dried seaweed were also determined. C18:1 (83.59%), followed by C16:0 and C18:2, were the most abundant fatty acids in camellia oil. A total of 11 and 32 volatile compounds were identified in camellia oil and sesame oil, respectively. In the preference test, the camellia oil samples received a higher, although insignificant, liking rating in overall acceptability of appearance. Overall, there were no differences between the sensory attributes of camellia oil and sesame oil. This finding, combined with the unique fatty acid composition, thermal stability, and health benefits of camellia oil indicate that further study into the use of camellia oil in foods is warranted.

Development and Usability Evaluation of A Virtual Reality-Based Vestibular Rehabilitation System for Balance Enhancement (균형감각 증진용 가상현실 기반 전정재활 시스템 개발 및 사용성 평가 )

  • Geun-Hong Park;Hyun-Min Lee
    • Journal of the Korean Society of Physical Medicine
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    • v.18 no.4
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    • pp.155-162
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    • 2023
  • PURPOSE: The primary objective of this study was to develop a virtual reality-based vestibular rehabilitation system to enhance balance perception, target rehabilitation specialists, and evaluate its usability. A key goal was establishing a system refinement strategy based on the collected data. METHODS: We conducted a study involving ten adults aged 10 to 29 in Gwangju Metropolitan City to evaluate the usability of a virtual reality-based vestibular rehabilitation system to enhance balance perception. After introducing the product and explaining its use to the participants, balance assessments and training were conducted using computerized dynamic posturography (CDP) (also called the test of balance [TOB]). Subsequently, participants were given a questionnaire to evaluate subjective stability, operability, and satisfaction. Frequency analysis was utilized to determine the frequency of the variable values of the measurement items in the survey for descriptive statistics. RESULTS: We found that the average usability score was 2.587. When broken down by category, stability received an average rating of 2.725, operability scored an average of 2.783, and satisfaction averaged 2.454. These findings suggest that most participants experienced positive sentiments and considerable satisfaction. CONCLUSION: The study successfully developed a virtual reality-based vestibular rehabilitation system, which was an improvement over the previous model and addressed its shortcomings. The results show that users with vestibular impairments are satisfied and more engaged with this system, indicating that additional studies are warranted.

The Effects of Music Therapy Program on Problem Behaviors and Social Skills Children with ADHD (음악치료 프로그램이 ADHD 성향 아동의 문제행동 개선과 사회적 기술향상에 미치는 효과)

  • Shin, Ji Hye;Yoon, Duk Sun
    • Korean Journal of Childcare and Education
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    • v.7 no.2
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    • pp.137-158
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    • 2011
  • This study is to investigate the effect of music therapy Program on Problem Behaviors and Social Skills Children with ADHD. The participants of the study were first and second graders in B elementary school in J city. They were observed in unsuitable behavioral patterns in school life by their homeroom teachers. Fifteen participants were divided into control and experimental group: The control group was eight and the experimental group was seven. Group music therapy was conducted two times a week for seven-week period. It took 35-40 minutes per therapy after school. Child Behavior Checklist-Korean, Social Skills Rating System, Social Acceptance were administered in pre- and post-stages. For the analysis of the data, Mann-Whitney U test was used. The findings from the research are summarized as follows: 1) The experimental group who was treated in music therapy showed a positive effect on problem behaviors. That is to say, the participants in the experimental group improved in emotional and cognitive stability while they significantly decreased attack behaviors; 2) The experimental group statistically showed significant improvement in their social behaviors compared to the control group. The music therapy group significantly increased social skills such as cooperation, self-assertion, and self-control. However, they did not improve responsibility as social skills in a significant manner; and 3) The experimental group showed higher degree of social acceptance than the control group. However, the result did not show a significant difference between the groups. In conclusion, the study proved positive effects of music therapy on ADHD children's uncarefulness, attack behaviors, and social skills for seven-week experimental period.

Radial Variation in Selected Wood Properties of Indonesian Merkusii Pine

  • Darmawan, Wayan;Nandika, Dodi;Afaf, Britty Datin Hasna;Rahayu, Istie;Lumongga, Dumasari
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.4
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    • pp.323-337
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    • 2018
  • Merkusii pine wood (Pinus merkusii) was extensively planted throughout Indonesia, where it is only indigenous in northern Sumatera, by the Dutch during colonial times. The demand for this wood species, especially in the domestic market, has increased notably, despite its limited durability regarding decay resistance. The purpose of this study was to investigate the occurrence of juvenile and mature wood on merkusii pine and to analyze its radial features from pith to bark based on density, shrinkage, static bending in modulus of rupture and modulus of elasticity, fiber length, microfibril angle, and durability. A segmented modeling approach was used to find the juvenile-mature transition. The graveyard test was performed to characterize the termite resistance from pith to bark of merkusii pine. The maturations were estimated to start at radial increments of 15 cm from the pith by fiber length and of 12 cm from the pith by microfibril angle. The projected figures for the proportion of juvenile wood at breast height were around 65%. The results also indicate that the pine wood was $0.52g/cm^3$ in density, 1.45 in coefficient of anisotropy, which indicates its good stability, 7597 MPa in modulus of elasticity, and 63 MPa in modulus of rupture. Natural durability against subterranean termite of the merkusii pine wood was rated to be grade 4 to 0 from pith to bark. However, after being treated by Entiblu and Enborer preservatives, its rating increased to grade 10 to 9.

A Case Series of Snake Venom Pharmacopuncture for Chemotherapy-Induced Peripheral Neuropathy: A Retrospective Observational Study

  • Song, Si Yeon;Bae, Kyeore;Shin, Kwhang Ho;Yoo, Hwa-Seung
    • Journal of Pharmacopuncture
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    • v.20 no.4
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    • pp.280-286
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    • 2017
  • Objective: This case series aims to report the efficacy and the safety of using snake venom pharmacopuncture (SVP) for chemotherapy-induced peripheral neuropathy (CIPN). Methods: Three heterogeneous cancer (1 endometrium, 1 cervix, and 1 prostate cancer) patients were referred to the East-West Cancer Center (EWCC), Dunsan Korean Medicine Hospital of Daejeon University, from August 02, 2017, to September 15, 2017, for treatment with SVP, and they were treated with SVP 4 times, 6 times, and 8 times, respectively. During the treatment period, the efficacy of SVP therapy was assessed by using the Numerical Rating Scale (NRS) and the Common Terminology Criteria for Adverse Events (CTCAE), and the stability was evaluated by using blood tests. Following each session, all patients were examined closely for any allergenic responses or adverse effects. Results: All patients showed noticeable improvements of their NRS and CTCAE scores. Except for bleeding and bruising at the SVP injection site, no major side effects were noted. One of the patients reported mild chilling and a sore throat after receiving the second treatment; those symptoms went away after a few hours. No hematologic toxicity, hepatotoxicity, or nephrotoxicity was found on the blood test. Conclusion: The results of this research suggest positive potential benefits of using SVP for treating patients with CIPN. Also, the excellent safety results of SVP seen in this research should lead to larger clinical trials aimed at developing SVP into a potential intervention for managing patients with the symptoms of CIPN.

The Effect of Non-face-to-Face Class due to COVID-19 on Academic Stress and Back Pain in University StudentsThe Effect of Non-face-to-Face Class due to COVID-19 on Academic Stress and Back Pain in University Students

  • Kim, Yoo Rim;Kim, Dong Hoon
    • Physical Therapy Rehabilitation Science
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    • v.11 no.1
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    • pp.43-48
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    • 2022
  • Objective: In the present study, to determine the extent of academic stress and pain from sitting for a long time, we will use a questionnaire to examine the effects of non-face-to-face stress and back pain on college students who have conducted non-face-to-face lectures. Design: Survey research Methods: A questionnaire was conducted using Naver foam to identify academic stress, attitude and time to listen to lectures, and the extent of back pain for college students who are experiencing non-face-to-face lectures. Outcome measures include the scale of academic stress (SAS), the Numeric rating scale (NRS), the Oswestry Disability Index (ODI Korea version) was implemented. The difference in academic stress was analyzed by t-test and one-way ANOVA, and the correlation between academic stress and back pain was analyzed using the Spearman correlation coefficient. In order to examine the academic stress, consistency, and stability, the reliability of the academic stress items was measured by examining the reliability with the Cron-Bach alpha coefficient. Allstatistical significance levels were α=0.05. Results: According to the general characteristics of the subject, there were no statistically significant results compared to gender (P<0.05), but the higher the grade, the higher the stress index, the higher the level of pain. Conclusions: This study confirmed that non-face-to-face lectures caused by COVID-19 have increased academic stress and the resulting increase in back pain in college students.

A Study on the Efficiency of National Policy Bank's Support for SMEs Policy Funds (국책은행의 중소기업 정책자금 지원에 관한 효율성 연구)

  • Yun, Mi;Lee, Cheol-Gyu
    • Journal of Digital Convergence
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    • v.18 no.10
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    • pp.147-162
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    • 2020
  • The purpose of this study is to present practical improvement plans for policy fund support in national policy banks through an analysis of the efficiency of policy fund support. It targets small and medium-sized enterprises(SMEs) that received policy funding from national policy banks in '17 and '18 consecutively. As for the analysis method, characteristic analysis and corresponding sample T-test was performed. The analysis results are as follows. First, as a result of analyzing the characteristics of small and medium-sized enterprises, most of the financial funds were concentrated on the manufacturing industry. By region, the western region of Gyeonggi Province, by credit rating, was A grade, technology grade was T5, and the use of funds was mostly concentrated on facility funds. Second, as a result of efficiency analysis, profitability had a positive effect on total capital return, stability had a positive effect on interest compensation ratio, and activity had a positive effect on total capital turnover. In conclusion, it is expected to provide practical improvement plans to support policy funds to influence the growth and distribution of funds appropriate to the needs of SMEs.

Development of Predictive Models for Rights Issues Using Financial Analysis Indices and Decision Tree Technique (경영분석지표와 의사결정나무기법을 이용한 유상증자 예측모형 개발)

  • Kim, Myeong-Kyun;Cho, Yoonho
    • Journal of Intelligence and Information Systems
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    • v.18 no.4
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    • pp.59-77
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    • 2012
  • This study focuses on predicting which firms will increase capital by issuing new stocks in the near future. Many stakeholders, including banks, credit rating agencies and investors, performs a variety of analyses for firms' growth, profitability, stability, activity, productivity, etc., and regularly report the firms' financial analysis indices. In the paper, we develop predictive models for rights issues using these financial analysis indices and data mining techniques. This study approaches to building the predictive models from the perspective of two different analyses. The first is the analysis period. We divide the analysis period into before and after the IMF financial crisis, and examine whether there is the difference between the two periods. The second is the prediction time. In order to predict when firms increase capital by issuing new stocks, the prediction time is categorized as one year, two years and three years later. Therefore Total six prediction models are developed and analyzed. In this paper, we employ the decision tree technique to build the prediction models for rights issues. The decision tree is the most widely used prediction method which builds decision trees to label or categorize cases into a set of known classes. In contrast to neural networks, logistic regression and SVM, decision tree techniques are well suited for high-dimensional applications and have strong explanation capabilities. There are well-known decision tree induction algorithms such as CHAID, CART, QUEST, C5.0, etc. Among them, we use C5.0 algorithm which is the most recently developed algorithm and yields performance better than other algorithms. We obtained data for the rights issue and financial analysis from TS2000 of Korea Listed Companies Association. A record of financial analysis data is consisted of 89 variables which include 9 growth indices, 30 profitability indices, 23 stability indices, 6 activity indices and 8 productivity indices. For the model building and test, we used 10,925 financial analysis data of total 658 listed firms. PASW Modeler 13 was used to build C5.0 decision trees for the six prediction models. Total 84 variables among financial analysis data are selected as the input variables of each model, and the rights issue status (issued or not issued) is defined as the output variable. To develop prediction models using C5.0 node (Node Options: Output type = Rule set, Use boosting = false, Cross-validate = false, Mode = Simple, Favor = Generality), we used 60% of data for model building and 40% of data for model test. The results of experimental analysis show that the prediction accuracies of data after the IMF financial crisis (59.04% to 60.43%) are about 10 percent higher than ones before IMF financial crisis (68.78% to 71.41%). These results indicate that since the IMF financial crisis, the reliability of financial analysis indices has increased and the firm intention of rights issue has been more obvious. The experiment results also show that the stability-related indices have a major impact on conducting rights issue in the case of short-term prediction. On the other hand, the long-term prediction of conducting rights issue is affected by financial analysis indices on profitability, stability, activity and productivity. All the prediction models include the industry code as one of significant variables. This means that companies in different types of industries show their different types of patterns for rights issue. We conclude that it is desirable for stakeholders to take into account stability-related indices and more various financial analysis indices for short-term prediction and long-term prediction, respectively. The current study has several limitations. First, we need to compare the differences in accuracy by using different data mining techniques such as neural networks, logistic regression and SVM. Second, we are required to develop and to evaluate new prediction models including variables which research in the theory of capital structure has mentioned about the relevance to rights issue.