• 품질경영학회지
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• 제31권2호
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• pp.165-182
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• 2003

The fatigue has been considered to the most important failure mode where optimal design or reliability prediction of the machinery in aircraft, atomic reactors, and structure systems, etc., is required. When the statistical analysis of fatigue life data is performed, some difficulties are present because of the following facts : nonlinear relationship, heteroscedastic data, large scatter in the data, censored data (runouts), and existence of fatigue limit. To find the S-N curve models that characterize fatigue strength better, this research compares existing fatigue curve models developed recently in terms of the residual mean square and the estimate of fatigue limit, etc. for various fatigue data sets.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.141-148
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• 2002

Repair were made for front pillar, center pillar and side-step panel for lightweight vehicles with head-on and 40% off-set collision of 15 km/h in a RCAR standard. The salt dilution was sprayed and the compression tests were performed for vehicles with and without anti-corrosional treatment after repair. After 764 hours of salt-dilt sprayed test without using anti-corrosion, the mean penetration depth fur corrosion was shown to be 58% of the thickness. The resulyed decrease in bending stiffness by 10∼20% can cause reduction of the residual life and crash-absorption capability for damaged vehicles. The corrosoin safety tests showed that the anti-corrosional treatment should be made to improve the safety characteristics for a or damaged car.

• Clinics in Shoulder and Elbow
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• 제26권2호
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• pp.109-116
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• 2023

Background: Golf is a popular sport involving overhead activity and engagement of the rotator cuff (RC). This study aimed to determine to what level golfers were able to return to golf following RC repair, the barriers to them returning to golf and factors associated with their failure to return to golf. Methods: Patients preoperatively identifying as golfers undergoing RC repair at the study centre from 2012 to 2020 were retrospectively followed up with to assess their golf-playing status, performance and frequency of play and functional and quality of life (QoL) outcomes. Results: Forty-seven golfers (40 men [85.1%] and 7 women [14.9%]) with a mean age of 56.8 years met the inclusion criteria, and 80.1% were followed up with at a mean of 27.1 months postoperatively. Twenty-nine patients (76.3%) had returned to golf with a mean handicap change of +1.0 (P=0.291). Golf frequency decreased from a mean of 1.8 rounds per week preinjury to 1.5 rounds per week postoperatively (P=0.052). The EuroQol 5-dimension 5-level (EQ-5D-5L) index and visual analog scale (EQ-VAS) score were significantly greater in those returning to golf (P=0.024 and P=0.002), although functional outcome measures were not significantly different. The primary barriers to return were ipsilateral shoulder dysfunction (78%) and loss of the habit of play (22%). Conclusions: Golfers were likely (76%) to return to golf following RC repair, including mostly to their premorbid performance level with little residual symptomatology. Return to golf was associated with a greater QoL. Persistent subjective shoulder dysfunction (78%) was the most common barrier to returning to golf.

• 여성건강간호학회지
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• 제28권3호
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• pp.210-221
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• 2022

Purpose: The purpose of this study was to construct a hypothetical model based on Meleis and colleagues' Transition Theory and a literature review to explain women's menopausal transition, constructing a modified model considering previous studies and model fit and testing the effects between variables. Methods: With a correlational survey design, middle-aged Korean women aged 40 to 64 years who had experienced menopausal symptoms were recruited and filled out a self-administered study questionnaire. Measures included menopausal symptoms, resilience, social support, menopause management, menopause adaptation, and quality of life. The data were analyzed using SPSS 24.0 and AMOS 24.0. Results: The model fit indices were considered acceptable: 𝛘²/degree of freedom=2.93, standardized root mean residual=.07, comparative fit index=.90, and parsimonious normed fit index=.73. All eight direct-effect paths-from menopausal symptoms to support and adaptation, from support to adaptation and resilience, from resilience to adaptation and management, from management to quality of life, and from adaptation to quality of life-were significant. The explanatory power of the menopause transition model was 63.6%. Conclusion: Women who experience menopausal symptoms may be able to maintain and improve their quality of life if menopause management and menopause adaptation are successful through resilience and social support. Future research is needed to confirm whether strengthening facilitation as a nursing intervention strategy may promote healthy response patterns.

• 한국치위생학회지
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• 제11권5호
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• pp.629-636
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• 2011

Objectives : The purpose of this study was to determine the effects of oral health on the quality of life of elderly patients with dentures or implants. It is our intention that through this analysis we can aid seniors in making the choice between dentures or implants, considering future masticatory function and the likely effects of this decision on the patients quality of life. Methods : This survey was conducted between November 1, 2010 and November 25, 2010, in Kyunggi-Do, whasung city. The research was carried out at one public health center, among elderly patients. 105 seniors were surveyed using the direct interviewing method, oral health related quality of life was measured by the Philadelphia Geriatric Center(PGC) Morale Scale. Collected data was examined using the SPSS 13.0 program, using frequency, mean, and standard deviation analysis, T-test and $x^2$ test. Results : The number of residual teeth for patients who have implants was $20.45{\pm}5.85$, while among those patients with dentures the number was considerably lower, $8.11{\pm}7.66$(p<0.05). The results of patients masticatory function, was $28.13{\pm}2.40$ for those with implants, and $25.35{\pm}4.15$ with dentures. The results were better for those with implants. Among implant patients overall satisfaction was rated $25.21{\pm}3.63$, higher than for those with dentures $20.20{\pm}6.79$(p<0.05). Quality of life was scored higher for patients with implants($12.76{\pm}2.61$) compared to those with dentures($10.47{\pm}3.52$)(p<0.05). The subjects masticatory function was highly related to the number of remaining teeth and greater masticatory function had a positive effect on patients quality of life and life satisfaction. Conclusion : Dental treatments such as dentures and implants will have a great influence on patients quality of life and life satisfaction. Implants can improve the oral health related quality of life and satisfaction and the general quality of life more than denture therapy.

• 대한간호학회지
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• 제22권4호
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• pp.476-490
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• 1992

This study was designed to develop and test a structural model for maternal adaptation and family stress in families with mentally handicapped children. A hypothetical model was constructed on the basis of the family stress theory developed by McCubbin etc. The model included 6 theoretical concepts and 11 paths. For the purpose of the model testing, empirical data were collected from May to August, 1992. The subjects of the study constituted 190 mothers of children in five special schools and one private institute in Seoul and Choong Nam. An SPSS PC＋ and PC－LISREL 7.13 computer programs were used for descriptive and covariance structure analysis. The results of the study were as follows. (1) The hypothetical model showed itself a good fit to the empirical data ［Chi - square＝18.35(df＝7, P＝0.005), Goodness of Fit Index＝0.991, Adjusted Goodness of Fit Index＝0.959, Root Mean Square Residual＝0.042), Non Normed Fit Index＝0.90, Normed Fit Index＝0.96］. (2) The results of Hypothesis testing indicated : 1) Social support(${\gamma}$$_{11}$＝.238, T＝2.352), Family functioning(${\gamma}$$_{12}$＝.729, T＝5.957) and Family life event stress(${\gamma}$$_{13}$＝.125) had direct effects on situational definition. 2) Life event stress(${\gamma}$$_{23}$＝.319, T＝3.872) had direct effects on the effect of the handicapped child on the family. Family functioning(${\gamma}$$_{22}$＝-.245) and situational definition($\beta$$_{21}$＝-.335, T＝3.227) had direct effects on the effect of the handicapped child on the family. 3) Situational definition($\beta$$_{31}$＝-.273, T＝3.493), family life event stress (${\gamma}$$_{33}$＝.124, T＝2.169) and the effect of the handicapped child on the family($\beta$$_{32}$＝.264, T＝-3.227) showed the direct effect on the maternal adaptation. The model was supported by the empirical data. Thus it was suggested that the model could be applied to family nursing care with the families with the mentally handicapped. The construction and testing of the comprehensive model seem to be the first trial in Korea.a.a.a.

• Steel and Composite Structures
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• 제36권1호
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• pp.75-86
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• 2020

The grid structures with welded hollow spherical joint (WHSJ) have gained increasing popularity for use in industrial buildings with suspended cranes, and usually welded with steel tube (ST). The fatigue performance of steel tube-welded hollow spherical joint (ST-WHSJ) is however not yet well characterized, and there is little research on fatigue life prediction methods of ST-WHSJ. In this study, based on previous fatigue tests, three series of specimen fatigue data with different design parameters and stress ratios were compared, and two fatigue failure modes were revealed: failure at the weld toe of the ST and the WHSJ respectively. Then, S-N curves of nominal stress were uniformed. Furthermore, a finite element model (FEM) was validated by static test, and was introduced to assess fatigue behavior with the hot spot stress method (HSSM) and the effective notch stress method (ENSM). Both methods could provide conservative predictions, and these two methods had similar results. However, ENSM, especially when using von Mises stress, had a better fit for the series with a non- positive stress ratio. After including the welding residual stress and mean stress, analyses with the local stress method (LSM) and the critical distance method (CDM, including point method and line method) were carried out. It could be seen that the point method of CDM led to more accurate predictions than LSM, and was recommended for series with positive stress ratios.

• 농약과학회지
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• 제11권3호
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• pp.154-163
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• 2007

우리나라 배추에 등록되어 사용중인 pyrethroid계 살충제 중 bifenthrin과 lambda-cyhalothrin 및 deltamethrin의 얼갈이배추 중 경시적 잔류특성을 구명하기 위하여 시험 농약을 기준량과 배량으로 살포한 후 시료를 경시적으로 채취하여 잔류농약을 분석하였다. 시험농약의 검출한계는 모두 0.004 mg $kg^{-1}$이었으며, 평균 회수율은 0.04 mg $kg^{-1}$에서 95.16-99.32%, 0.20 mg $kg^{-1}$에서 86.81-103.73%이었다. 시험농약의 반감기는 기준량 처리구에서는 2.5-3.6일, 배량 처리구에서는 2.3-3.9일 이었다. Bifenthrin과 lambda-cyhalothrin의 기준량과 배량 처리구 및 deltamethrin의 기준량 처리구의 살포직후 농도는 잔류허용기준 미만이었으나 deltamethrin의 배량 처리구에서는 잔류허용기준을 초과하였다. 그러나 수확예정일의 시료중 시험농약의 농도는 모두 잔류허용기준 미만이었으며, 수확예정일의 잔류량으로 산출한 시험농약의 ADI 대비 EDI의 비율이 기준량과 배량 처리구에서 모두 7% 미만으로 안전한 것으로 평가되었다.

• 농약과학회지
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• 제13권1호
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• pp.13-20
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• 2009

배추에 등록되어 일반적으로 사용하고 있는 살충제 etofenprox와 methoxyfenozide를 살포하여 생물학적 소실곡선식을 통한 수확 전 약제살포 후 경과일수별 잔류량을 예측하였다. 두 시험 농약의 검출한계는 $0.01mg\;kg^{-1}$이었고, 분석법의 회수율은 etofenprox와 methoxyfenozide에서 각각 96.76-95.84%, 94.50-103.26%이었다. 시험농약의 반감기는 기준량 처리구에서 etofenprox와 methoxyfenozide에서 각각 3.2일, 3.5일 이었고, 배랑 처리구에서는 각각 2.7일, 3.5일 이었다. 시험 농약의 약제 살포직후 농도는 잔류허용기준을 초과하였으나, 수확예정일의 시료중 시험농약의 농도는 모두 잔류허용기준 미만이었으며, 수확예정일의 잔류량으로 산출한 시험농약의 ADI 대비 EDI의 비율은 기준량과 배량 처리구에서 모두 4%미만으로 안전한 것으로 평가되었다.

• Ocean and Polar Research
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• 제39권1호
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• pp.13-21
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• 2017

Temporal changes in the number of zooplankton species are important information for understanding basic characteristics and species diversity in marine ecosystems. The aim of the present study was to estimate the optimal monitoring frequency (OMF) to guarantee and predict the minimum number of species occurrences for studies concerning marine ecosystems. The OMF is estimated using the temporal number of zooplankton species through bi-weekly monitoring of zooplankton species data according to operational taxonomic units in the Tongyoung coastal sea. The optimal model comprises two terms, a constant (optimal mean) and a cosine function with a one-year period. The confidence interval (CI) range of the model with monitoring frequency was estimated using a bootstrap method. The CI range was used as a reference to estimate the optimal monitoring frequency. In general, the minimum monitoring frequency (numbers per year) directly depends on the target (acceptable) estimation error. When the acceptable error (range of the CI) increases, the monitoring frequency decreases because the large acceptable error signals a rough estimation. If the acceptable error (unit: number value) of the number of the zooplankton species is set to 3, the minimum monitoring frequency (times per year) is 24. The residual distribution of the model followed a normal distribution. This model can be applied for the estimation of the minimal monitoring frequency that satisfies the target error bounds, as this model provides an estimation of the error of the zooplankton species numbers with monitoring frequencies.