• 한국인터넷방송통신학회논문지
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• 제9권4호
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• pp.139-144
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• 2009

최근의 여러분야에서 검색되어지고 있는 인터넷 도메인 용어의 전문성의 표시화는 온톨리지를 통한 지식의 축적의 목표가 되고 있다. 도메인 용어의 중요성을 표시화 한다면 기계가 온톨리지를 이용하여 정보의 관리 및 해석을 스스로 하는 것이 가능할 것으로 본다. 본 논문에서는 온톨로지의 중요성 (weight)을 구성하는 속성을 확장된 퍼지를 사용하여 기존 웹문서의 구조정보로부터 추출하는 알고리즘을 제안하였다. 특히 속성정보로 구성된 도메인 지식을 표시화 함으로써 속성추출 알고리즘을 개선하고, 추출결과의 품질을 향상시킨다. 5만문서를 대상으로 제안된 알고리즘을 적용한 결과 약 94%의 신뢰도의 속성정보를 추출할 수 있었다.

• 시스템엔지니어링학술지
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• 제19권2호
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• pp.18-31
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• 2023

Exploring artificial intelligence and machine learning for nuclear safety has witnessed increased interest in recent years. To contribute to this area of research, a machine learning model capable of accurately predicting nuclear power plant response with minimal computational cost is proposed. To develop a robust machine learning model, the Best Estimate Plus Uncertainty (BEPU) approach was used to generate a database to train three models and select the best of the three. The BEPU analysis was performed by coupling Dakota platform with the best estimate thermal hydraulics code RELAP/SCDAPSIM/MOD 3.4. The Code Scaling Applicability and Uncertainty approach was adopted, along with Wilks' theorem to obtain a statistically representative sample that satisfies the USNRC 95/95 rule with 95% probability and 95% confidence level. The generated database was used to train three models based on Recurrent Neural Networks; specifically, Long Short-Term Memory, Gated Recurrent Unit, and a hybrid model with Long Short-Term Memory coupled to Convolutional Neural Network. In this paper, the System Engineering approach was utilized to identify requirements, stakeholders, and functional and physical architecture to develop this project and ensure success in verification and validation activities necessary to ensure the efficient development of ML meta-models capable of predicting of the nuclear power plant response.

• 한국대기환경학회지
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• 제22권1호
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• pp.117-126
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• 2006

The purpose of this study is to develop a badge-type passive sampler for the measurement of short-term nitrogen dioxide and to evaluate its performance. The principle of the method is a colorimetric reaction of nitrogen dioxide with sulfanilic acid, N-1-naphthylethylendiamine, and phosphoric acid. First, it has been shown that the filter paper should be rinsed with ultrapure water and ultrasound, and then dried in a vacuumed desiccator. The concentration and volume of absorption reagent (triethanolamine) were $20\%$ and 100 ${\mu}L$, respectively. The extraction time was determined as 60 min. Second, duplicate measurements (n= 116) were carried out for evaluating the precision of the passive sampler. The relative error and the correlation coefficient between duplicates are $3.4\pm 3.0\%$ and 0.994, respectively. In addition, the $95\%$ confidence interval of intraclass correlation coefficient and the estimated value are 0.992$\sim$0.996 and 0.994, respectively. Third, a paired t-test was carried out for evaluating the accuracy of the passive sampler (n=40). In the result of the test, the $95\%$ confidence interval of the difference was -1.710 ppb <$\gamma$< 0.788 ppb. Finally, the average concentration of blanks, measurement detection limit, limit of detection, and limit of quantification are $2.4\pm 0.4$ ppb, 104 ppb, 3.8 ppb, and 7.0 ppb, respectively.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3390-3399
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• 2013

본 연구는 2009년 한 해 동안 건강보험심사평가원의 요양급여 전체 청구자료를 통계적으로 표본 추출 한 환자표본자료를 이용하여 의료기관 종류 별 욕창 발생현황과 이중 요양병원 환자의 욕창 발생에 영향을 주는 요인을 규명하기 위해 시도되었다. 전체 의료기관 입원환자의 3.2%(n=25,339)에서 욕창이 발생하였다. 의료기관 종별로는 요양병원 입원환자의 8.2%(n=11,895)에서 욕창이 발생하여 종합병원(2.7%, n=8,052), 일반병원(1.7%, n=5,059) 보다 상대적으로 높은 비율을 보였다. 요양병원 입원환자(n=144,523)의 욕창발생에 영향을 주는 요인을 분석한 결과 의학적 진단 중 요실금을 가진 환자 군이 가지지 않은 군에 비해 욕창 발생이 2.46배 유의하게 높게 나타났다(Odds ratio(OR)=2.462, 95% confidence interval(CI)=2.038-2.974). 더하여, 고혈압질환(OR=1.456, CI=1.400-1.515), 말초혈관 질환(OR=1.357, CI=1.200-1.534)군 순으로 욕창 발생에 영향을 미쳤다. 진단 수(OR=1.193, CI=1.187-1.199)와 나이(OR=1.011, CI=1.009-1.012) 및 100침상 당 의사 수(OR=1.063, CI=1.035-1.091)가 증가할수록, 의료기관의 전체 침상수(OR=.889, CI =.869-.909)가 적을수록 욕창발생은 유의하게 높은 것으로 나타났다.

• 국제물리치료학회지
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• 제11권3호
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• pp.2155-2163
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• 2020

Background: Various treatments have been proposed for chronic low back pain (CLBP), but recent guidelines and reviews recommend regular physical exercise. However, some other studies have reported opposite results that sling exercise (SE) and other exercises (OE) did not differ in improving CLBP. Objectives: To systematically review and meta-analyze the effects of SE on CLBP in studies published in Korea. Design: A Systemic Review and Meta-analysis. Methods: Randomized controlled trials comparing SE with OE and modality therapy (MT), published up to June 2020, were identified by electronic searches. Primary outcomes were pain and disability. The weighted mean difference (WMD), stand mean difference (SMD) and 95% confidence interval (CI) were calculated using a random-effects model. Results: Based on the results of the meta-analysis, SE was effective for pain in the comparison of SE and MT [short-term: WMD=-1.64, 95% CI (-3.06, -0.22); long-term: WMD=-0.34, 95% CI (-0.42, -0.26)]. It was effective for pain in the comparison of SE and OE [short-term: WMD=-1.18, 95% CI (-2.15, -0.20); long-term: WMD=-0.66, 95% CI (-0.89, -0.43)]. It was also effective for disability in the comparison of SE and MT [short-term: SMD=-15.82, 95% CI (-23.10, -8.54)]. We found no clinically relevant differences in disability between SE and OE. Heterogeneity was high in the comparison of SE and overall variables. Conclusion: If SE is applied to physical therapy to improve the main symptoms of CLBP patients, it may contribute to their recovery. More high-quality randomized studies on the topic are warranted.

• Safety and Health at Work
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• 제5권4호
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• pp.186-190
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• 2014

Background: Physical exercise during leisure time is known to increase physical capacity; however, the long-term effects on work ability and work strain are inconclusive. The aim of this study was to investigate the effects of a 6-month physical exercise program on work ability and work strain after 6 months and 30 months, among women with menopausal symptoms at baseline. Methods: A questionnaire including questions on work ability and work strain was mailed in the beginning, at 6 months and after 30 months after the intervention to occupationally active women participating in a randomized controlled study on physical exercise and quality of life. The intervention included aerobic exercise training 4 times per week, 50 minutes per session. Work ability was measured with the Work Ability Index (WAI) and with questions about physical and mental work strain. Results: Women aged 47-62 years (N=89) who were occupationally active at baseline were included in the analyses. The increase in WAI from baseline to the end of the exercise intervention (6 months) was statistically significantly greater among the intervention group than among the control group (regression coefficient 2.08; 95% confidence interval 0.71-3.46). The difference between the groups persisted for 30 months. No significant short- or long-term effects on physical and mental work strain were found. Conclusion: A 6-month physical exercise intervention among symptomatic menopausal women had positive short-term as well as long-term effects on work ability.

• The Korean Journal of Pain
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• 제32권3호
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• pp.215-222
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• 2019

Background: Several nerve blocks can reduce the incidence of postherpetic neuralgia (PHN) as well as relieve acute zoster-related pain, but the long-term outcome of PHN has not been clearly determined. This study investigated the efficacy of selective nerve root block (SNRB) for herpes zoster (HZ) on the long-term outcome of PHN. Methods: We prospectively conducted an interview of patients who had undergone an SNRB for HZ from January 2006 to December 2016 to evaluate their long-term PHN status. The relationship between the time from HZ onset to the first SNRB and the long-term outcome of PHN was investigated. Results: The data of 67 patients were collected. The patients were allocated to acute ($SNRB{\leq}14days$, n = 16) or subacute (SNRB > 14 days, n = 51) groups. The proportions of cured patients were 62.5% and 25.5% in the acute and subacute groups (P = 0.007), respectively. In logistic regression, an SNRB >14 days was the significant predictor of PHN (adjusted odd ratio, 3.89; 95% confidence interval, 1.02-14.93; P = 0.047). Kaplan-Meier analysis revealed that time from the SNRB to the cure of PHN was significantly shorter in the acute group ($2.4{\pm}0.7yr$) than in the subacute group ($5.0{\pm}0.4yr$; P = 0.003). Conclusions: An early SNRB during the acute stage of HZ (within 14 days) appears to decrease the incidence and shorten the duration of PHN, with a median of 5.0 years of follow-up.

• Clinics in Shoulder and Elbow
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• 제26권2호
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• pp.175-181
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• 2023

Background: Acromioclavicular (AC) osteoarthritis (OA) is a frequent pathology of the shoulder in elderly patients. Drug injection plays an important role in treatment of AC OA. Literature has demonstrated excellent short-term results regarding shoulder function and pain. However, mid- to long-term results are lacking. The aim of this study was to assess the efficacy of a single intra-articular AC injection in patients with AC OA and to identify predictive factors for success. Methods: A retrospective study was performed to analyze success rate, shoulder function, and pain perception after a single intra-articular injection in patients with AC OA. Success was defined as the absence of reinterventions such as additional injection or surgery. Outcome measures were 1-year success rate and clinical outcome scores of Numeric Rating Scale (NRS) for pain, Oxford Shoulder Score, and Subjective Shoulder Value. Results: Ninety-eight patients participated in this study. At a median final follow-up of 0.8 years (interquartile range, 0-6), 57 of these patients (58%) had undergone a reintervention. The 1-year success rate was 47% (95% confidence interval, 37%-57%), with NRS at rest as the sole factor significantly associated with success. Thirty patients not requiring reintervention reported significant improvement from baseline for all reported outcome measures at final follow-up. Conclusions: AC injections offer a 1-year success rate of 47%. The AC injection produces good mid- to long-term clinical outcomes regarding shoulder function, quality of life, and pain perception in one-third of patients. Further research is essential to analyze mid- to long-term outcomes of AC injections.

• Journal of Gastric Cancer
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• 제23권4호
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• pp.584-597
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• 2023

Purpose: This study aimed to investigate the impact of different types of complications on long-term survival following total gastrectomy for gastric cancer. Materials and Methods: A total of 926 patients who underwent total gastrectomy between 2008 and 2016 were included. Patients were divided into the morbidity and no-morbidity groups, and long-term survival was compared between the 2 groups. The prognostic impact of postoperative morbidity was assessed using a multivariate Cox proportional hazard model, which accounted for other prognostic factors. In the multivariate model, the effects of each complication on survival were analyzed. Results: A total of 229 patients (24.7%) developed postoperative complications. Patients with postoperative morbidity showed significantly worse overall survival (OS) (5-year, 65.0% vs. 76.7%, P<0.001) and cancer-specific survival (CSS) (5-year, 74.2% vs. 83.1%, P=0.002) compared to those without morbidity. Multivariate analysis adjusting for other prognostic factors showed that postoperative morbidity remained an independent prognostic factor for OS (hazard ratio [HR], 1.442; 95% confidence interval [CI], 1.136-1.831) and CSS (HR, 1.463; 95% CI, 1.063-2.013). There was no significant difference in survival according to the severity of complications. The following complications showed a significant association with unfavorable long-term survival: ascites (HR, 1.868 for OS, HR, 2.052 for CSS), wound complications (HR, 2.653 for OS, HR, 2.847 for CSS), and pulmonary complications (HR, 2.031 for OS, HR, 1.915 for CSS). Conclusions: Postoperative morbidity adversely impacted survival following total gastrectomy for gastric cancer. Among the different types of complications, ascites, wound complications, and pulmonary complications exhibited significant associations with long-term survival.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.51.1-51.15
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• 2023

Background: Recently, there has been increasing worldwide concern about outdoor air pollution, especially particulate matter (PM), which has been extensively researched for its harmful effects on the respiratory system. However, sufficient research on its effects on cardiovascular diseases, such as hypertension, remains lacking. In this study, we examine the associations between PM levels and hypertension and hypothesize that higher PM concentrations are associated with elevated blood pressure. Methods: A total of 133,935 adults aged ≥ 40 years who participated in the Korean Genome and Epidemiology Study were analyzed. Multiple linear regression analyses were conducted to investigate the short- (1-14 days), medium- (1 and 3 months), and long-term (1 and 2 years) impacts of PM on blood pressure. Logistic regression analyses were conducted to evaluate the medium- and long-term effects of PM on blood pressure elevation after adjusting for sex, age, body mass index, health-related lifestyle behaviors, and geographic areas. Results: Using multiple linear regression analyses, both crude and adjusted models generated positive estimates, indicating an association with increased blood pressure, with all results being statistically significant, with the exception of PM levels over the long-term period (1 and 2 years) in non-hypertensive participants. In the logistic regression analyses on non-hypertensive participants, moderate PM₁₀ (particulate matter with diameters < 10 ㎛) and PM_2.5 (particulate matter with diameters < 2.5 ㎛) levels over the long-term period and all high PM₁₀ and PM_2.5 levels were statistically significant after adjusting for various covariates. Notably, high PM_2.5 levels of the 1 year exhibited the highest odds ratio of 1.23 (95% confidence interval: 1.19-1.28) after adjustment. Conclusions: These findings suggest that both short- and long-term exposure to PM is associated with blood pressure elevation.