• Title/Summary/Keyword: Reliability prognosis

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SOH Estimation and Feature Extraction using Principal Component Analysis based on Health Indicator for High Energy Battery Pack (건전성 지표 기반 주성분분석(PCA)을 적용한 고용량 배터리 팩의 열화 인자 추출 방법 및 SOH 진단 기법 연구)

  • Lee, Pyeong-Yeon;Kwon, Sanguk;Kang, Deokhun;Han, Seungyun;Kim, Jonghoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.25 no.5
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    • pp.376-384
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    • 2020
  • An energy storage system is composed of lithium-ion batteries in modern applications. Batteries are regarded as storage devices for renewable and residual energy. The failure of batteries can cause the performance reduction and explosion of battery systems. High maintenance cost is essential when dealing with the problem of battery safety. Therefore an accurate health diagnosis is required to ensure the high reliability of battery systems. A battery pack is a combination of single cells in series and parallel connections. A battery pack has to consider various factors to assess battery health. Battery health involves conventional factors and additional factors, such as cell-to-cell imbalance. For large applications, state-of-health (SOH) can be inaccurate because of the lack of factors that indicate the state of the battery pack. In this study, six characterization factors are proposed for improving the SOH estimation of battery packs. The six proposed characterization factors can be regarded as health indicators (HIs). The six HIs are applied to the principal component analysis (PCA) algorithm. To reflect information regarding capacity, voltage, and temperature, the PCA algorithm extracts new degradation factors by using the six HIs. The new degradation factors are applied to a multiple regression model. Results show the advancement and improvement of SOH estimation.

Clinical Practice Patterns for Carpal Tunnel Syndrome in Korean Medicine: An Online Survey (손목터널증후군의 한의 임상 진료 현황 조사를 위한 온라인 설문조사)

  • Lee, Sang-Hyun;Park, Hye-Jin;Kim, Hyun-Tae;Park, Sun-Young;Heo, In;Hwang, Man-Suk;Shin, Byung-Cheul;Hwang, Eui-Hyoung
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.16 no.1
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    • pp.73-89
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    • 2021
  • Objectives We conducted an online survey to understand the current status of Korean Medicine clinical practice related to carpal tunnel syndrome (CTS) to develop the CTS Korean Medicine Clinical Practice Guidelines (CPG). Methods A thoroughly reviewed questionnaire was distributed by e-mail to 21,719 Korean Medicine doctors between March 26 and April 30, 2021. All raw data were arranged and analyzed systematically. Results The response rate among the doctors was 4%. Of the respondents, 82.1% responded that it is necessary to develop the CTS Korean Medicine CPG. We also obtained data related to the specific diagnosis, treatment, and prognosis management methods used at various treatment sites for patients with CTS. Conclusions This online survey will be helpful in developing the CTS CPG, which will contribute to the standardization of guidelines and improvements in the reliability of Korean Medicine. Our findings will provide valuable data and resources for future clinical studies on CTS.

Clostridioides difficile Infection in a Japanese Tertiary Children's Hospital

  • Meguro, Mariko;Nambu, Ryusuke;Hara, Tomoko;Ebana, Ryo;Yoshida, Masashi;Yamamoto, Saki;Mori, Koki;Iwama, Itaru
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.25 no.5
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    • pp.387-395
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    • 2022
  • Purpose: Toxins produced by Clostridioides difficile infection (CDI) can cause enteritis and diarrhea. Although the number of pediatric CDI cases is increasing, the clinical management of pediatric CDI, including patient characteristics and prognosis, remains unclear. This study aimed to elucidate the background and clinical course of patients with CDI and evaluate the reliability of diagnostic tests in a tertiary pediatric hospital in Japan. Methods: We retrospectively analyzed the clinical data of children diagnosed with CDI between 2011 and 2021 at the Saitama Children's Medical Center in Saitama, Japan. Results: During the study period, 1,252 C. difficile antigen/toxin tests were performed, and 37 patients were diagnosed with CDI. The main underlying diseases among the patients were hematological and malignant disorders and gastrointestinal diseases, including inflammatory bowel disease (IBD) (59.4%). Two patients (5.4%) had an unremarkable medical history. Among the 37 patients, 27 (73.0%) were immunocompromised, 25 (67.6%) had a history of antibiotic use within the past two months, and 6 (16.2%) were negative on the initial test but were positive on the second test. Finally, 28 patients (75.7%) required primary antibiotic therapy only, and two patients with IBD required additional antibiotic therapy as secondary treatment. Conclusion: The number of pediatric patients with CDI is increasing. Both a comprehensive interview, including underlying diseases and history of antibiotic use, and an understanding of the features of clinical examinations should be emphasized to appropriately diagnose and treat CDI.

What is the interobserver agreement of displaced humeral surgical neck fracture patterns?

  • Reinier W. A. Spek;Laura J. Kim
    • Clinics in Shoulder and Elbow
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    • v.25 no.4
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    • pp.304-310
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    • 2022
  • Background: The Boileau classification distinguishes three surgical neck fracture patterns: types A, B, and C. However, the reproducibility of this classification on plain radiographs is unclear. Therefore, we questioned what the interobserver agreement and accuracy of displaced surgical neck fracture patterns is categorized according to the modified Boileau classification. Does the reliability to recognize these fracture patterns differ between orthopedic residents and attending surgeons? Methods: This interobserver study consisted of a randomly retrieved series of 30 plain radiographs representing clinical practice in a level 1 and a level 2 trauma center. Radiographs were included from patients (≥18 years) who sustained an isolated displaced surgical neck fracture if they were taken ≤1 week after initial injury. A ground truth was established by consensus among three senior orthopedic surgeons. All images were assessed by 17 orthopedic residents and 17 attending orthopedic trauma surgeons. Results: Agreement for the modified Boileau classification was fair (κ=0.37; 95% confidence interval [CI], 0.36-0.38) with an accuracy of 62% (95% CI, 57%-66%). Comparison of interobserver variability between residents and attending surgeons revealed a significant but clinically irrelevant difference in favor of attending surgeons (0.34 vs. 0.39, respectively, Δκ=0.05, 95% CI, 0.02-0.07). Conclusions: The modified Boileau classification yields a low interobserver agreement with an unsatisfactory accuracy in a panel of orthopedic residents and attending surgeons. This supports the hypothesis that surgical neck fractures are challenging to categorize and that this classification should not be used to determine prognosis if only plain radiographs are available.

Development of a Breast Cancer Awareness Scale for Thai Women: Moving towards a Validated Measure

  • Rakkapao, Nitchamon;Promthet, Supannee;Moore, Malcolm A;Hurst, Cameron P
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.2
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    • pp.851-856
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    • 2016
  • Background: Breast cancer is a major health problem among women around the world. Recent developments in screening and treatment have greatly improved the prognosis of patients with breast cancer in developed countries. However, in developing countries breast cancer mortality remains high.Breast cancer awareness is a first and important step in reducing breast cancer mortality. The development of a validated instrument to measure breast cancer awareness is crucial for the understanding and implementation of suitable health education programs to facilitate early deletion and minimize mortality. Objective: The objective of this study was to develop an instrument for the assessment of breast cancer awareness in Thai women. Materials and Methods: This methodological study was conducted in two stages: (1) literature searches and semi-structured interviews were conducted to generate items of the breast cancer awareness scale (B-CAS) which were subsequently examined for content and face validity, and (2) an exploration of the factor structure of the resulting instrument and an examination of its reliability. Data were collected using a self-administered questionnaire in Thai women aged 20-64 in August, 2015. Results: A total of 219 women (response rate 97.4 %) participated in this validation study. The B-CAS contains five domains with 53 items on breast cancer awareness: 1) knowledge of risk factors, 2) knowledge of signs and symptoms, 3) attitude to breast cancer prevention, 4) barriers of breast screening, and 5) health behavior related to breast cancer awareness. Items with a content validity index < 0.80 were excluded, and factor structure for the remaining items reflected the hypothesized five factor model. The scales based on all retained items was shown to have strongly internal consistency reliability (Cronbach's ${\alpha}=0.86$). Conclusions: The B-CAS provides good psychometric properties to assess breast cancer awareness in women. It can be used to examine breast cancer awareness in Thai women and it could lead to the development and evaluation of suitable educational interventions for raising breast cancer awareness. Future research should focus on further validating the B-CAS including an assessment of construct and criterion-based validity.

A Study on the Perceived Stress of Mothers in Neonatal Intensive Care Unit (신생아 중환자실에 입원한 환아 어머니의 스트레스)

  • Choi Sung Hee
    • Child Health Nursing Research
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    • v.4 no.1
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    • pp.60-75
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    • 1998
  • The parents have much expectation upon the pregnancy and child birth, and in most cases, they expect the healthy parturient child. However, we can be placed on the high-risk conditions which have the physical, social and immature infant, due to the unexpected results, among the new-born. Accordingly, these high-risk newborn and premature infants will be mostly in NICU, which the concentrated medical treatment can be given, upon their conditions. After their birth and during these periods, they will be divided from the parents, and the nurse will accomplish the bringing-up activities which they can take care of the infant, expected by the parents after their birth. The hospitalization of high-risk newborn including these premature infants is the shocking experience to the parents of family, and thus they can feel the fear and uneasiness, and these reactions of parents are troubled in the behavior at the usual days, and cause the disorder and spiritless status, and these results break the supporting ability of parents, and cause the obstruction. Also, the unavoidable division between the parents and the children as like hospitalization of children can make the parents to feel the alienation emotionally, and this causes the results which the pride on the bringing-up ability of baby gets to be lost. These problems can cause the difficulties on the bonding or the parenting in the further days, and can be related to the neglect and abuse of children. Also, it is gradually increased to study and report which the emotional division by the physical division between the mother and the baby obstructs the normal affection course between the parent and the infant. The stress caused by the birth and the hospitalization of high-risk newborn, as like this, is important in the points which it can uncertainly affect the potential energy for the relationship of parent-child who are finally healthy. Accordingly, the significance and purpose of this study are to understand the contents and degree of stress which the parents of high-risk newborn including the immature child can be experienced from the hospitalization of ICU for their new borns, and thus to offer the basic program to the nursing intervention program for these. The subject of this study is the mother of newborn in NICU of 10 General Hospitals located at the 3one of Pusan, Korea from September 1997 to October 1997, and thus makes the subject of 95 person of parents who agreed to take part in the study and it is descriptive study related to the stress of mother having the newborn in NICU. The method is based on the preceding study related to the stress of mother having the experience of child hospitalization and chronic disease child, and then acquires the advice of specialists group as like 5 nursing professors, and then is amended and supplemented. Total number of questions is 43 items and consists of 5 factors as like medical treatment &nursing procedures, disease status & prognosis, role of parents, communication & inter-personal relationships, hospital environment, and is 5 point Likert Scale. The reliability of this study method is very highly shown to be Cronbach α=0.95. The collected data is analysed as Average, Frequency, Standard Deviation, T-test, ANOVA, Pearson Correlation Coefficient, Duncan multifulrange test by use of SPSS /PC (V7.5). The results of this study is summarized as under. 1. Every characteristics of subject is which the party of mother is 28.70age(±7.48) in the average ages, 51% in the high-school graduate, 38.5% in the christianity, total monthly income is 212.55 thousand won(±1.971), 74.5% in the housewife, 72.9% in the parents and children together living and the number of children to be 1.48person(± 0.6) in average, the recognition on the prognosis of baby is 74.0% in 'Don't know', the relationship with the husband after the hospitalization of babyis 37.3% in 'More Intimate', the relationship with the family of husband to be 48% in 'No-change', and the degree which is consulted with the husband about the baby is 55% in 'very frequently' and the visiting number per week is 4.59(±1.63) in average and the accompanying person in the time of visiting is which the number of husband is 56.3% and thus is the highest. The characteristics of baby is which the age is 21.88days(±16.47) after the birth in average, the sex to be 50 person in the female 52.1% and the order of birth to be 54.2% in the first chid, and the weight in the birth to be 2770gm(±610) and the height in the birth to be 46.26cm(±7.62) in aver age. The medical diagnosis is 37.5% in the premature infant, the career of hospitalization is 96.9% in 'None', and the operation plan is 90.6% in 'None' and the execution of operation is 88% in 'None' and the nursing of incubator is 55.2% in 'Yes', and the method of feeding is 50.5% in 'Oral' and the contents of feeding is 46.9% in the 'Milk'. 2. The total stress degree of subject is almost highly shown to be as 3.36(±0.86). If it is compared upon each cause, 'stress on disease status & prognosis' is highest 3.79(±1.28), and it is in the order of 'stress on medical treatment & nursing procedures' 3.70(±0.93), 'stress on hospital environment' 3.14(±0.86), 'stress on role of parents' 3.18(±0.92) and 'stress on communication & inter personal relationship' 2.62(± 0.77) 3. As the results of checking the notworthiness of stress degree upon each variable of subject, the variable showing the noted difference was the birth weight(γ=-0.16, P=0.04), birth height(γ=-0.23, P=0.03), nursing in the incubator(F=8.93, P=0.04), feed method(F=2.94, P=0.04). That is to say, it is shown which the smaller the birth weight is, the higher the stress degree of mother is noteworthily. Also, the smaller the birth height baby is, the higher the stress of mother is. In the incubator, it os shown which the mother whose baby is nursing in the incubator is higher in the stress degree than other mothers. Upon the feeding method of baby, that is to say, TPNis the highest, and it is shown in the order of NPO, Tube feeding, and P.O. feeding. When we review the above-mentioned results, as the status is serious, it is thought which we include the supporting nursing for coping with the stress of parents in the setting-up od nursing plan for the baby in the NICU.

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Feature Extraction for Bearing Prognostics based on Frequency Energy (베어링 잔존 수명 예측을 위한 주파수 에너지 기반 특징신호 추출)

  • Kim, Seokgoo;Choi, Joo-Ho;An, Dawn
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.2
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    • pp.128-139
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    • 2017
  • Railway is one of the public transportation systems along with shipping and aviation. With the recent introduction of high speed train, its proportion is increasing rapidly, which results in the higher risk of catastrophic failures. The wheel bearing to support the train is one of the important components requiring higher reliability and safety in this aspect. Recently, many studies have been made under the name of prognostics and health management (PHM), for the purpose of fault diagnosis and failure prognosis of the bearing under operation. Among them, the most important step is to extract a feature that represents the fault status properly and is useful for accurate remaining life prediction. However, the conventional features have shown some limitations that make them less useful since they fluctuate over time even after the signal de-noising or do not show a distinct pattern of degradation which lack the monotonic trend over the cycles. In this study, a new method for feature extraction is proposed based on the observation of relative frequency energy shifting over the cycles, which is then converted into the feature using the information entropy. In order to demonstrate the method, traditional and new features are generated and compared using the bearing data named FEMTO which was provided by the FEMTO-ST institute for IEEE 2012 PHM Data Challenge competition.

The Comparative Study of Alveolar Bone Level and Root Form of the Mandibular Molar on Radiographic Image and Clinical Examination (방사선사진과 임상검사에서 하악 대구치 치근의 형태학적 구조 및 치조골 수준에 관한 비교연구)

  • Park, Jung-Bae;Chung, Chin-Hyung
    • Journal of Periodontal and Implant Science
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    • v.34 no.2
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    • pp.281-292
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    • 2004
  • Periodontal defects of the furcation are characterized by several inherent anatomic factors that can make successful periodontal therapy difficult and results unpredictable. The severity and rate of occurrence of periodontal disease are directly related to the location of the furcation relative to the cementa-enamel junction and anatomical form of the root by limiting the accessibility and effectiveness of the periodontal instrumentation. This study investigated the reliability and accuracy of panoramic radiograph diagnoses of the periodontal state of mandibular molars, particularly regarding the diagnosis of furcation area periodontal defects, treatment planning, and prognosis prediction. This study examined a total of 110 teeth belonging to 33 subjects (19 male, 14 female) presenting with incipient to moderate periodontitis 4-7mmpocket depth. The alveolar bone level, length and width of the root trunk, and root separation angle were measured using the panoramic radiograph and compared to the results taken directly by retracting a full-thickness flap. The results of the study are as follows: 1. Data regarding the alveolar bone level of the mandibular first molar showed that the directly taken surgical measurements resulted in $5.1{\pm}0.9mm$ that was slightly deeper than the corresponding panoramic measurement resulted in $4.8{\pm}0.8mm$, but these differences were statistically insignificant (p>0.05). 2. The data of the directly taken surgical measurement of the mandibular second molar $(5.1{\pm}1.1mm)$ was slightly deeper than the corresponding panoramic measurement $(4.7{\pm}1.2mm)$, but these differences were statistically insignificant (p>0.05). 3. The measured values of the length and width of the mandibular first molar root trunks were determined to be $4.1{\pm}0.6mm$ and $7.3{\pm}0.9mm$, respectively, while the values of the mandibular second molar root trunks were determined to be $4.6{\pm}1.3mm$ and $7.6{\pm}0.9mm$ respectively. The differences between these values were found to be statistically significant (p<0.01). 4. The measured values of the root separation angle showed that the mandibular first molars averaged $34.5{\pm}4.4^{\circ}$, while the mandibular second molars averaged $23.0{\pm}10.0^{\circ}$. The differences between these values were found to be statistically significant (p<0.01).

Uncertainty, Self-Efficacy & Coping in Parents′ of Children with Cancer (암환아 부모의 질병에 대한 불확실성, 자기효능감 및 대처정도)

  • Oh Won Oak;Park Eun Sook
    • Child Health Nursing Research
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    • v.4 no.2
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    • pp.274-285
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    • 1998
  • Improvements in therapy have resulted in increasing numbers of children being successfully treated for cancer. However the agrressiveness of therapy & uncertainty about prognosis are associated with many adverse effects, psychological as well as physical for both the child & family. The purpose of this study were to measure the degree of perceived uncertainty, self-efficacy & coping, and then to examine the relationship between the perceived uncertainty, self-efficacy & coping in parents of children cancer patients. The subjects of this study consist of 140 parents with pediatric cancer, registered at pediatric cancer ward & Out Patient Department. Data was collected from July 1st to August 15th 1998. The tools used in this study were Mishel's the Parents' Perception of Uncertainty Scale (28 item, 4 likert scale), Shere's Self-Efficacy Scale (17 item, 5 likert scale) & Folkman & Lazarus Ways of Coping Checklist(34 items, 4 likert scale). Data was analyzed by t-test, Anova, Pearson Correlation coefficient. Results of this study are summerized as follows 1. Parents perceived their uncertainty to be slightly high(Mn 2.41). The degree of perceived uncertainty by the four components were followed as lack of clarity (2.60), unpredictability(2.59), ambiguity(2.51) & lack of information(1.90). The degree of perceived uncertainty of parents with pediatric cancer revealed to be influenced significantly by the family outcome, reliability about health care provider & perceived severity of illness. 2. The range of parents' self-efficacy was measured iron 35 to 85 point, so revealed slightly high. The degree of self-efficacy related to be Influenced signiicantly by the sequency of child birth, family religion & degree of perceived support. 3. The degree of parents' coping was measured slightly high (Mn 2.78). The degree of coping related to be influnced significantly by the sequency of child birth, number of sible & degree of perceived support. 4. parents' uncertainty was related inversely to the parents' self-efficacy(r=-.38, p<.001) & coping(r=-.26, p<.001). And also parents' self-efficacy was positively related to coping(r=.56, p<.001) From the above results, it can be concluded that predicting & controlling parents' uncertainty with children cancer are necessary to improve positive coping strategies. This information may be used as a foundation for developing nursing interventions to decrease perceived uncertainty & to foster self-efficacy & coping for parents with children cancer.

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Accuracy of three-dimensional periodontal ligament models generated using cone-beam computed tomography at different resolutions for the assessment of periodontal bone loss

  • Hangmiao Lyu;Li Xu;Huimin Ma;Jianxia Hou;Xiaoxia Wang;Yong Wang;Yijiao Zhao;Weiran Li;Xiaotong Li
    • The korean journal of orthodontics
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    • v.53 no.2
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    • pp.77-88
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    • 2023
  • Objective: To develop a method for generating three-dimensional (3D) digital models of the periodontal ligament (PDL) using 3D cone-beam computed tomography (CBCT) reconstruction and to evaluate the accuracy and agreement of the 3D PDL models in the measurement of periodontal bone loss. Methods: CBCT data collected from four patients with skeletal Class III malocclusion prior to periodontal surgery were reconstructed at three voxel sizes (0.2 mm, 0.25 mm, and 0.3 mm), and 3D tooth and alveolar bone models were generated to obtain digital PDL models for the maxillary and mandibular anterior teeth. Linear measurements of the alveolar bone crest obtained during periodontal surgery were compared with the digital measurements for assessment of the accuracy of the digital models. The agreement and reliability of the digital PDL models were analyzed using intra- and interexaminer correlation coefficients and Bland-Altman plots. Results: Digital models of the maxillary and mandibular anterior teeth, PDL, and alveolar bone of the four patients were successfully established. Relative to the intraoperative measurements, linear measurements obtained from the 3D digital models were accurate, and there were no significant differences among different voxel sizes at different sites. High diagnostic coincidence rates were found for the maxillary anterior teeth. The digital models showed high intra- and interexaminer agreement. Conclusions: Digital PDL models generated by 3D CBCT reconstruction can provide accurate and useful information regarding the alveolar crest morphology and facilitate reproducible measurements. This could assist clinicians in the evaluation of periodontal prognosis and establishment of an appropriate orthodontic treatment plan.