• 대한의생명과학회지
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• 제23권2호
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• pp.118-127
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• 2017

Elevated serum uric acid and resting heart rate are risk factors and predictors of metabolic syndrome. However, few studies have examined the optimal cutoff value for serum uric acid and resting heart rate to predict metabolic syndrome in Korean adults. Subjects for this study were 22,302 adults (average age 45 years old), who underwent health screening examination from January 2010 to December 2012 at the Health Promotion Center of one hospital in Gyeonggi-do for general health check-up. The uric acid and resting heart rate cutoff values were calculated by ROC analysis for metabolic syndrome. Elevated serum uric acid and resting heart rate were associated with an increased prevalence of metabolic syndrome in Korean adults. The optimal cutoff value for uric acid level to predict metabolic syndrome in adults was 4.95 mg/dL (male 6.35, female 4.55) and optimal cutoff value for resting heart rate to predict metabolic syndrome was 68 beats per minute (male 66, female 68). However, serum uric acid and resting heart rate were found to have limitations for the diagnosis of metabolic syndrome.

• Communications for Statistical Applications and Methods
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• 제19권4호
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• pp.629-638
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• 2012

We propose some methods to obtain optimal thresholds and classification functions by using various cutoff criterion based on the bivariate ROC curve that represents bivariate cumulative distribution functions. The false positive rate and false negative rate are calculated with these classification functions for bivariate normal distributions.

• 한국통신학회논문지
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• 제17권10호
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• pp.1100-1108
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• 1992

AJ 시스템의 비트 오류 확률의 정확한 계산은 매우 어렵거나 불가능하므로 비트 오류 확률의 Chernoff상한을 구하여 시스템의 성능 분석을 하는 것이 매우 유용하다. 부호 채널에 대한 cutoff rate의 계산은 비교적 용이하므로, AJ 시스템의 부호화 비트 오율의 상한은 AWGN 채널에서의 비트오율의 상한이 cutoff rate의 항으로 직접 구해지는 관계를 이용하여 구할 수 있다. 본 논문에서는 부호 기법을 적용한 통신 시스템에 대하여 적용할 수 있는 비트 오류 확률의 상한에 대한 일반적인 표현식을 소개하고 그 결과를 이용하여 Trumpis 부호를 적용한 FH/MFSK 시스템의 광대역 및 부분 대역 잡음 재밍에 대한 성능 분석을 하였고 아울러 채널 측정을 통해 부가적으로 제공될 수 있는 재머의 상태 정보가 비트 오류 확률에 미치는 효과도 계산함으로써 위의 사실을 입증하였다.

• 농업과학연구
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• 제30권1호
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• pp.89-101
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• 2003

For the pre-feasibility study and project evaluation, the discount rate or cutoff rate should be given by the government authority. To get the Benefit/Cost Ratio, NPV(Net Present Value) and IRR(Internal Rate of Return) of the public investment projects, the pertinent and realistic discount rate should be determined to be suitable to the present time period. The cut-off rates in Korea were equivalent to 15% in 1970's, 10% in 1980's and 8% in 1990's. The prevailing rate of discount as 8% is considered not to be suitable for the 2000's public project appraisal considering the present interest rates on deposit and national bonds. To determine the socio-economic feasibility of the public projects, the IRR should be bigger than the present cutoff rate. When we still use the high old rate of discount, the analytical results of project appraisal will show always economically unfeasible. Therefore the new rate of discount suitable for present time should be determined by the government. The public projects to be implemented in 2000 year onward are recommended to be adapted 5% of cutoff rate for the project appraisal and evaluation according to the results of reviewing the tendency of discount rates and market rates of interest in Korea.

• 한국시뮬레이션학회논문지
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• 제6권2호
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• pp.117-124
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• 1997

A simulation model for the estimation of cutoff connection rate in the asynchronous transfer mode (ATM) switching system under multimedia traffic environments is presented. The simulator is developed by the integration of the AweSim tool with user-written C++ routines that model the internal structures of operational details of the switching system. For the case study, the simulator is applied to the ATM switching system developed by Electronics and Telecommunications Research Institute (ETRI) to compare design alternatives according to the cutoff connection rates.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1655-1658
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• 2014

Objective: To find a more appropriate alternative to D-dimer cutoff value for the diagnosis of deep vein thrombosis (DVT) in cancer patients. Methods: A total of 711 cancer patients with symptoms suspicious of DVT were included in the study. D-dimer levels were assessed using ELISA. All patients were subjected to imaging procedures. Results: Among 711 patients with cancer, 466 (65.5%) were females and 245 (34.5%) were males, with an average age of $57.3{\pm}13.23$ years. The mean age in the DVT group was significantly higher than in the non-DVT group (P<0.05). The D-dimer levels of the DVT group were significantly higher than those of the non-DVT group (P<0.05). The incidence rate of DVT varied significantly according to cancer type (P<0.05). Increasing age and lung cancer were significantly correlated with D-dimer levels (P<0.05), and a one-year increase in age was associated with a 14.28 ng/ml increase in the D-dimer value. The optimal cutoff point for D-dimer was found to be 981 ng/ml, with a sensitivity of 86.4%, specificity of 79.4%, and accuracy of 82.6%. If the D-dimer cutoff point was set to 981ng/ml, the specificity would increase from 61.8% to 85.5% without loss of sensitivity in patients aged 40 years or younger. In patients aged more than 40 years, the new cutoff almost doubled the specificity with slightly reduced sensitivity. Conclusion: In cancer patients, a new cutoff value of 981 ng/ml effectively improved the exclusion of DVT, especially for patients aged more than 40 years.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1996년도 학술대회
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• pp.17-22
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• 1996

• 대한의용생체공학회:의공학회지
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• 제25권2호
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• pp.137-144
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• 2004

심전도 신호에는 근 잡음과 전원잡음 둥의 잡음이 섞이는 경우가 많다. 이러한 잡음들은 심전도 신호의 주요 주파수 성분에 비하여 상대적으로 고주파 성분이지만 전체적으로 보면 주파수 스펙트럼이 중첩된다. 본 논문에서는 연속적으로 변하는 차단주파수를 가지는 시변 저역통과 디지털필터를 이용하여 원신호의 왜곡을 최소화하면서 잡음을 제거하는 신호처리 방법에 대하여 기술한다 이 필터는 차단주파수 제어기와 가변차단주파수 저역통과필터로 구성된다. 차단주파수 제어기는 잡음이 포함된 심전도 신호로부터 신호의 기울기를 이용하여 차단주파수 제어 신호를 생성한다. 가변차단주파수 저역통과필터의 구현을 위해서 본 논문에서는 컨벡스 조합 필터와 계수보간 필터로 불리는 새로운 두 가지 필터 설계방법을 제안하였으며, 이 두 가지 방법을 이용함으로써 저역통과필터의 차단주파수를 임의의 제한된 구간에서 연속적으로 변화시키는 것이 가능하였다. 고주파 잡음이 첨가된 심전도 신호에서 가변차단주파수 저역통과필터의 잡음 제거 능력이 우수함을 보였으며, 본 논문에서 제안된 가변차단주파수 저역퉁과필터는 심전도 신호의 전처리에 유용하게 사용되어질 것으로 판단된다. 특히, 제어된 환경이 아닌 일상생활 환경에서 심전도를 측정하는 재택건강관리 시스템에서 신호의 품질을 개선하는 데에 효과가 있을 것으로 기대한다.

• 한국조리학회지
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• 제20권5호
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• pp.1-10
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• 2014

The employment rate has become the standard for university values. This raises the need to investigate the antecedents of university students' career exploration. Focused on the hospitality majored students, this study aims to investigate both individual and relational factors that influence their career exploration behaviors. Differentiation of self has been chosen as the individual and the relational antecedents based on Bowen's theory. It was investigated whether each dimension(I-position, emotional reactivity, fusion with others, and emotional cutoff) explains the amount of self-exploration and the amount of environmental exploration. The university students majoring in hospitality were surveyed and a total of 269 cases out of 300 cases were analyzed employing descriptive statistics and multi-variate analysis of variance, and structural equation modeling(SEM). The study found that I-position positively influenced self-exploration and environmental exploration. Emotional reactivity made an influence on environmental exploration, while it failed to explain self-exploration. Fusion with others and emotional cutoff also significantly influenced environmental exploration, however, it didn't make any significant influence on self-exploration. This study implies that the college of hospitality majors needs to understand that differentiation of self forms through family relationship and needs to provide the students the programs of how to understand themselves and what to do for their career exploration.

• Journal of Korean Dental Science
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• 제16권1호
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• pp.47-62
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• 2023

Purpose: We aimed to investigate the objective cutoff values of unstimulated flow rates (UFR) and stimulated salivary flow rates (SFR) in patients with xerostomia and to present an optimal machine learning model with a classification and regression tree (CART) for all ages. Materials and Methods: A total of 829 patients with oral diseases were enrolled (591 females; mean age, 59.29±16.40 years; 8~95 years old), 199 patients with xerostomia and 630 patients without xerostomia. Salivary and clinical characteristics were collected and analyzed. Result: Patients with xerostomia had significantly lower levels of UFR (0.29±0.22 vs. 0.41±0.24 ml/min) and SFR (1.12±0.55 vs. 1.39±0.94 ml/min) (P<0.001), respectively, compared to those with non-xerostomia. The presence of xerostomia had a significantly negative correlation with UFR (r=-0.603, P=0.002) and SFR (r=-0.301, P=0.017). In the diagnosis of xerostomia based on the CART algorithm, the presence of stomatitis, candidiasis, halitosis, psychiatric disorder, and hyperlipidemia were significant predictors for xerostomia, and the cutoff ranges for xerostomia for UFR and SFR were 0.03~0.18 ml/min and 0.85~1.6 ml/min, respectively. Conclusion: Xerostomia was correlated with decreases in UFR and SFR, and their cutoff values varied depending on the patient's underlying oral and systemic conditions.