• Title/Summary/Keyword: Fatigue Assessment

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Finding Hazard Factors by New Risks on Maritime Safety in Korea

  • Park, Deuk-Jin;Park, Seong-Bug;Yang, Hyeong-Sun;Yim, Jeong-Bin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.3
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    • pp.278-285
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    • 2016
  • The key features of maritime accidents are the change of their attributes by new risks from time to time. To prevent maritime accidents in Korea, the impacts by new risks on domestic safety environments should be identified or predicted. The purpose of this paper is to find the hazard factors by new risks on maritime safety in Korea. The meaning of new risks is the elements of accident hazard which is compiled from new or rare or unprecedented events in the worldwide maritime transportations. The problems of new risks are the lacks of optimum countermeasures to mitigate accident risks. Using the questionnaires with 152 event scenarios classified by 20 accident causes, the hazard identification and risk analysis of new risks was performed based on the Formal Safety Assessment (FSA) by IMO. A total of 22 Influence Diagrams, which is to depict the transit flows between accident causes to consequences, is used in the construction of 152 event scenarios. A total of 20 accidents causes is the same contents as the causation factors represented in Statistical Year Book for Maritime Accidents of Korean Maritime Safety Tribunals. After defining the evaluation equations to the response results of questionnaires by 46 experts, the work for risk analysis is carried out. As results from the analysis of 152 scenarios, it is known that the root cause to affect on maritime safety in Korea is the pressure of business competition and it led to the lacks of well experienced crews, the overload of vessel operations and crew's fatigue. In addition, as results from the analysis of 20 accident causes, the three accident causes are to be candidate as main issues in Korea such as the inadequate preparedness of departure, the neglecting of watch keeping in bridge and the inadequate management of ship operations. All of the results are thought to be as basic hazard factors to safety impediments. It is thus found that the optimum Risk Control Options to remove the hazard factors and to mitigate consequences required are the following two factors: business competition and crewing problems.

Study of Quantitative Assessment Standard for Type 1 and Type 2 Gas Cylinders Using Acoustic Emission Testing (음향방출법을 이용한 Type 1 및 Type 2 가스실린더의 정량적 평가기준에 대한 연구)

  • Kim, Dong-Hyun;Lee, Sang-Bum;Kim, Kyung-Hoon;Yoon, Dong-Jin;Bae, Dong-Myung
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.2
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    • pp.176-183
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    • 2014
  • Acoustic emission testing (AET) of cylinders is advantageous in that it can be directly conducted on cylinders installed in a car, without needing to dissemble them on a real-time basis. Therefore, users prefer AET over other nondestructive testing methods. Owing to these advantages of AET, it has been approved by the Department of Transportation of the U.S. as a safety evaluation method for pressure containers or as an alternative to the hydroproof testing method. This paper presents a study of the quantitative evaluation criteria for a container having ultrasonic testing defects and also for Type 1 and Type 2 gas cylinders, which are defective seamless pressure containers provided by NK, a manufacturer of pressure containers. For the Type 1 cylinder, the process from crack growth to leak was observed in a repetitive fatigue test using a 113 L container according to ASTM E 1419-02. Further, for the Type 2 cylinder, integrity was evaluated using a 119 L sound container and a container damaged by hydraulic pressure, by the slow-fill method according to ASTM E 2191-02. Based on the AET results of the Type 1 and Type 2 cylinders, quantitative evaluation criteria were established for a defective and non-defective container.

Effectiveness Evaluation of Displacement Accommodatable Pressure Measuring Jig for Quality Assessment of Pressure Application Device (압력 인가 장치의 품질관리를 위한 변위 수용이 가능한 압력 측정용 지그의 유효성 평가)

  • Mun, Chang-Su;Jun, Sung-Chul;Noh, Si-Cheol
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.2
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    • pp.61-66
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    • 2020
  • Recently, a variety of electric anesthetics devices have been developed and used in clinical practice to reduce the fatigue of the operator during local anesthesia for dental procedures and to compensate for the disadvantages of manual anesthesia device. In this electric anesthesia injection device, the accurate and constant delivery of pressure for drug infusion is a very important performance factor. In order to evaluate the accuracy of the transfer pressure, a small pressure gauge using a load cell is often used, but since the elastic body inside the load cell may not be able to accommodate a sufficient displacement, an error may occur when evaluating pressure performance. For these reasons, in this study, we proposed and evaluated a silicon-chrome steel (Si-Cr steel) spring jig that can accommodate relatively large displacements that can be used when evaluating the performance of a pressure-controlled pressure application device using a load cell type pressure gauge. As a result of the pressure transmissibility test and repeated measurement results using a commercial dental anesthesia injection device, a more stable result was obtained when using a spring jig, and it was confirmed that the frequency of abnormally high measurement was reduced.

Effects of Custom Nutrition Education on Dietary Intakes and Clinical Parameters in Patients Diagnosed with Iron Deficiency Anemia (맞춤형 영양교육이 철결핍성 빈혈환자의 임상 지표 및 영양섭취 상태에 미치는 효과)

  • Kim, Hye-Jin;Mok, Hee-Jung;Hong, Jeong-Im;NamGung, Sin-A
    • Journal of the Korean Dietetic Association
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    • v.18 no.1
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    • pp.72-80
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    • 2012
  • This study examined the effects of custom nutrition education on dietary intakes and clinical parameters in patients diagnosed with iron deficiency anemia. A total of 34 patients visited the anemia clinic of Yeouido St. Mary's Hospital. Among these, only 16 patients were available for follow-ups. A follow-up was conducted by a clinical dietitian 2 months from the first nutrition education session. Patients were all women. For custom nutrition education, we investigated anthropometric data, dietary assessment (24 hr-recall, FFQ), and self-recognized anemic symptoms. Weight did not show a significant difference but hemoglobin, hematocrit (P<0.01), serum iron, and serum ferritin (P<0.05) were significantly increased after the nutrition education. Serum total iron binding capacity was significantly decreased (P<0.01). Self-recognized symptoms such as dizziness, fatigue (P<0.001), shortness of breath, headache (P<0.01), brittle nails, and sore tongue (P<0.05) were significantly improved. Daily intakes of protein (P<0.05), total iron (P<0.01), and animal iron (P<0.001) were significantly increased. A significantly negative correlation was observed between current serum iron and the intake of carbohydrates, fat, or phosphorus (P<0.05). But current serum ferritin showed a significantly positive correlation with the frequency of intake of meat, poultry, and fish. It could be concluded that the custom nutrition education might be effective on quality of diet as well as iron status and it might also improve the clinical parameters in patients diagnosed with the iron deficiency anemia.

Chemoradiation Related Acute Morbidity in Carcinoma Cervix and Correlation with Hematologic Toxicity: A South Indian Prospective Study

  • Kumaran, Aswathy;Guruvare, Shyamala;Sharan, Krishna;Rai, Lavanya;Hebbar, Shripad
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4483-4486
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    • 2014
  • Purpose: To assess chemoradiation related acute morbidity in women with carcinoma cervix and to find and correlation between hematologic toxicity and organ system specific damage. Materials and Methods: A prospective study was carried out between August 2012 and July 2013 enrolling 79 women with cancer cervix receiving chemo-radiotherapy. Weekly assessment of acute morbidity was done using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 4 and the toxicities were graded. Results: Anemia [77 (97.5%)], vomiting [75 (94.8%)] and diarrhea [72 (91.1%)], leukopenia [11 (13.9%)], cystitis [28 (35.4%], dermatitis [19 (24.1%)] and fatigue [29 (36.71%)] were the acute toxicities noted. The toxicities were most severe in $3^{rd}$ and $5^{th}$ week. All women could complete radiotherapy except two due to causes unrelated to radiation morbidity; seven (8.86%) had to discontinue chemotherapy due to leukopenia and intractable diarrhea. Though there was no correlation between anemia and other toxicities, it was found that all with leukopenia had diarrhea. Conclusions: Chemoradiation for cancer cervix is on the whole well tolerated. Leukopenia and severe diarrhea were the acute toxicities that compelled discontinuation of chemotherapy in two women. Though anemia had no correlation with gastrointestinal toxicity, all of those with leukopenia had diarrhea.

Factors Influencing Quality of Life during Chemotherapy for Colorectal Cancer Patients in South Korea (항암화학요법을 받고 있는 한국 대장암 환자의 삶의 질 영향 요인)

  • Baek, Yongae;Yi, Myungsun
    • Journal of Korean Academy of Nursing
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    • v.45 no.4
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    • pp.604-612
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    • 2015
  • Purpose: The purpose of this study was to investigate the levels of physical symptoms, anxiety, depression, and quality of life (QOL) during chemotherapy for colorectal cancer patients in South Korea and to identify factors influencing their QOL. Methods: Data were collected from 144 colorectal cancer patients receiving chemotherapy during 2012 at one general hospital located in Seoul. Physical symptoms were measured by the M. D. Anderson Symptom Inventory-Gastrointestinal Cancer Module, and anxiety and depression were measured by the Hospital Anxiety Depression Scale. QOL was measured by the Functional Assessment of Cancer Therapy-Colorectal. Data were analyzed using descriptive statistics, t-test, one-way ANOVA, $Scheff{\acute{e}}$ post hoc test, Pearson correlation and stepwise multiple regression. Results: Mean age of the participants was 56.6 and most of them were not employed. In terms of cancer stage, 38.2% were in stage 3, followed by stage 4 (34.7%). The most frequent symptom was lack of appetite, followed by sleep disturbance and fatigue. The mean score for anxiety was 5.40 with a prevalence of 23% and that of depression 8.85 with a prevalence of 64.6%. The mean score for quality of life was 81.93 out of 136 and 75.3% of the variance in QOL was explained by depression, symptoms, anxiety, treatment place, and occupational status. Depression was the strongest predictive factor. Conclusion: Oncology professionals need to pay special attention to relieving depression as well as physical symptoms to improve QOL during chemotherapy for colorectal cancer patients.

Analysis and probabilistic modeling of wind characteristics of an arch bridge using structural health monitoring data during typhoons

  • Ye, X.W.;Xi, P.S.;Su, Y.H.;Chen, B.
    • Structural Engineering and Mechanics
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    • v.63 no.6
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    • pp.809-824
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    • 2017
  • The accurate evaluation of wind characteristics and wind-induced structural responses during a typhoon is of significant importance for bridge design and safety assessment. This paper presents an expectation maximization (EM) algorithm-based angular-linear approach for probabilistic modeling of field-measured wind characteristics. The proposed method has been applied to model the wind speed and direction data during typhoons recorded by the structural health monitoring (SHM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. In the summer of 2015, three typhoons, i.e., Typhoon Chan-hom, Typhoon Soudelor and Typhoon Goni, made landfall in the east of China and then struck the Jiubao Bridge. By analyzing the wind monitoring data such as the wind speed and direction measured by three anemometers during typhoons, the wind characteristics during typhoons are derived, including the average wind speed and direction, turbulence intensity, gust factor, turbulence integral scale, and power spectral density (PSD). An EM algorithm-based angular-linear modeling approach is proposed for modeling the joint distribution of the wind speed and direction. For the marginal distribution of the wind speed, the finite mixture of two-parameter Weibull distribution is employed, and the finite mixture of von Mises distribution is used to represent the wind direction. The parameters of each distribution model are estimated by use of the EM algorithm, and the optimal model is determined by the values of $R^2$ statistic and the Akaike's information criterion (AIC). The results indicate that the stochastic properties of the wind field around the bridge site during typhoons are effectively characterized by the proposed EM algorithm-based angular-linear modeling approach. The formulated joint distribution of the wind speed and direction can serve as a solid foundation for the purpose of accurately evaluating the typhoon-induced fatigue damage of long-span bridges.

The Effect of Polyphenols Isolated from Cynanchi wilfordii Radix with Anti-inflammatory, Antioxidant, and Anti-bacterial Activity

  • Jeong, Sunyoung;Lee, Sunwoo;Choi, Woo Jin;Sohn, Uy Dong;Kim, Wonyong
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.2
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    • pp.151-158
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    • 2015
  • Recently, Cynanchi wilfordii Radix has gained wide use in Asian countries as a functional food effective for relieving fatigue, osteoporosis, and constipation, particularly in menopausal disorders. However, its anti-inflammatory and anti-microbial activities have not been explored in detail to date. The anti-inflammatory, antioxidant, and anti-bacterial properties of the Cynanchi wilfordii Radix extracts obtained with water, methanol, ethanol, and acetone were compared. All 4 polyphenol-containing extracts exhibited anti-inflammatory and antioxidant effects. The ethanol extract was found to elicit the most potent reduction of nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), and cytokine (IL-$1{\beta}$, IL-6, IL-10, and TNF-${\alpha}$) levels, as well as inhibit the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a concentration-dependent manner. The evaluation of antioxidant activity also revealed the ethanol extract to have the highest free radical scavenging activity, measured as $85.3{\pm}0.4%$, which is equivalent to 99.9% of the activity of ${\alpha}$ -tocopherol. In the assessment of anti-bacterial activity, only ethanol extract was found to inhibit the growth of the Bacillus species Bacillus cereus and Bacillus anthracis. These results show that polyphenols of Cynanchi wilfordii Radix have anti-inflammatory, antioxidant, and anti-bacterial properties that can be exploited and further improved for use as a supplementary functional food, in cosmetics, and for pharmaceutical purposes.

A comparison of ankle function between adults with and without Down syndrome

  • Yoon, Hyang-Woon;Yu, Tae-Ho;Seo, U-Hyeok;Lee, Jee-Won;Kim, So-Yeon;Chung, Soo-Jin;Chun, Hye-Lim;Lee, Byoung-Hee
    • Physical Therapy Rehabilitation Science
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    • v.6 no.4
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    • pp.182-188
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    • 2017
  • Objective: The purpose of this study was to compare ankle function between adults with and without Down syndrome (DS). Design: Cross-sectional study. Methods: Ten adults with DS and 18 without participated in this study and underwent manual muscle test (MMT), range of motion (ROM) assessment, star excursion balance test (SEBT), and functional movement screen (FMS). The tests were demonstrated to increase their accuracy and the actual measurements were assessed after one or two demonstrations. To minimize the standby time and fatigue, the travelled distance and measuring order were adjusted. To remove the influence of shoes on the measurements, the shoes were taken off and only socks were worn. Results: Dorsal and plantar flexion MMTs of both ankles were significantly weaker and plantar flexion ROM of both ankles were significantly lower in adults with DS compared with those without (p<0.05). However, dorsal flexion ROM of both ankles were not significantly different between them. There were significant differences in distances measured in all the directions (anterior, anterolateral, lateral, posterolateral, posterior, posteromedial, medial, and anteromedial directions) of SEBT (p<0.05). Significant differences were also demonstrated in the scores of hurdle step, inline lunge, shoulder mobility, and rotary stability among the seven items of FMS (p<0.05). Conclusions: To enhance the dynamic stability of adults with DS, it is necessary to improve ankle stability by strengthening the ankle dorsal and plantar flexors.

Study on the Microstructural Degradation of the Boiler Tubes for Coal-Fired Power Plants

  • Yoo, Keun-Bong;He, Yinsheng;Lee, Han-Sang;Bae, Si-Yeon;Kim, Doo-Soo
    • KEPCO Journal on Electric Power and Energy
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    • v.4 no.1
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    • pp.25-31
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    • 2018
  • A boiler system transforms water to pressured supercritical steam which drives the running of the turbine to rotate in the generator to produce electricity in power plants. Materials for building the tube system face challenges from high temperature creep damage, thermal fatigue/expansion, fireside and steam corrosion, etc. A database on the creep resistance strength and steam oxidation of the materials is important to the long-term reliable operation of the boiler system. Generally, the ferritic steels, i.e., grade 1, grade 2, grade 9, and X20, are extensively used as the superheater (SH) and reheater (RH) in supercritical (SC) and ultra supercritcal (USC) power plants. Currently, advanced austenitic steel, such as TP347H (FG), Super304H and HR3C, are beginning to replace the traditional ferritic steels as they allow an increase in steam temperature to meet the demands for increased plant efficiency. The purpose of this paper is to provide the state-of-the-art knowledge on boiler tube materials, including the strengthening, metallurgy, property/microstructural degradation, oxidation, and oxidation property improvement and then describe the modern microstructural characterization methods to assess and control the properties of these alloys. The paper covers the limited experience and experiment results with the alloys and presents important information on microstructural strengthening, degradation, and oxidation mechanisms.