• 한국통신학회논문지
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• 제36권3C호
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• pp.149-156
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• 2011

차세대 무선 이동통신 시스템의 높은 서비스 품질을 위한 방법으로 MIMO-OFDM(Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing)방식이 주목받고 있다. 그러나 OFDM 시스템에서와 같이 큰 PAPR(Peak-to-Average Power Ratio)이 중요한 문제이다. 본 논문에서는 PAPR의 감소를 위해, 새로운 위상시퀀스를 기반으로 한 적응형 P-SLM(Partitioned-SeLective Mapping) 기법을 제안한다. 제안된 기법은 새로운위상 시퀀스를 주기적으로 곱하고, 일정한 PAPR 임계치를 이용한 적응성으로 인해 PAPR성능 향상뿐만 아니라 복잡도 또한 감소한다. 모의 실험 결과 제안된 기법이 기존의 기법보다 PAPR 성능 뿐만 아니라 복잡도 또한 감소한 것을 확인 할 수 있었다.

• 대한의생명과학회지
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• 제25권3호
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• pp.256-266
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• 2019

In this study, obese adults were compared for their ability to predict obesity and lipid related variables and their optimal cutoff values to predict metabolic syndrome and insulin resistance. In this study, 9,256 adults aged 20 years or older and less than 80 years old, who were in the Gyeonggi region from January 2014 to December 2016 and who were examined at a general hospital, were enrolled. The diagnostic criteria for obesity were WHO (World Health Organization), and BMI $25kg/m^2$ or more presented in the Asia-Pacific region. Metabolic syndrome was diagnosed based on the criteria of American Heart Association / National Heart, Lung, and Blood Institute (AHA / NHLBI). According to the results of receiver operating characteristic curve (ROC) analysis, Triglyceride / HDL-cholesterol (TG / HDL-C), Triglyceride and Glucose (TyG) index, lipid accumulation product (LAP) and visceral adiposity index (VAI) showed high predictive power for diagnosing metabolic syndrome. The diagnostic accuracy of LAP (AUC: 0.854) for males and VAI (0.888) for females was the highest. The optimal cutoff value of LAP was 42.71 for male and 35.44 for female, and the cutoff value of VAI was 1.92 for male and 2.15 for female. In addition, WHtR (waist to height ratio), TyG index, and LAP were used as predictors of insulin resistance in obese adults. Therefore, LAP and VAI were superior to other indicators in predicting metabolic syndrome in obese adults.

• 한국환경보건학회지
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• 제32권1호
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• pp.8-18
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• 2006

The aim of this study is to evaluate the emission characteristics of mercury, lead, arsenic, and selenium from medium size municipal solid waste incinerators(MSWIs) in Korea. The concentrations of mercury, lead, arsenic, and selenium emitted from medium size MSWI stack were $2.67\;{\mu}g/Sm^3,\;0.38\;mg/Sm^3,\;1.33\;{\mu}g/Sm^3,\;0.28\;{\mu}g/Sm^3$, respectively. The concentration levels of mercury, lead, arsenic in flue gas from medium size MSW incinerator stacks selected were nearly detected under the Korea criteria level. Removal efficiencies of mercury, lead, arsenic, and selenium in waste heat boiler(WHE) and cooling tower(CT) were $90.36\%,\;69.76\%,\;43.04\%,\;40.64\%$, respectively. In general, the removal efficiencies of mercury and lead in WHE were higher than those of arsenic and selenium in WHE. Emission gas temperature reduction from waste heat boiler(WHB) and cooling tower(CT) can control mercury and lead of medium size MSWIs. To evaluate the relationship between mercury, lead, arsenic, selenium of fly ash and those of flue gas, it was carried out to correlation analysis of each metal concentration in the fly ash and in the flue gas from medium size MSWIs. From the correlation analysis, the coefficients of mercury, lead, arsenic, and selenium were 0.61, -0.38, 0.87, 0.28, respectively. The results of correlation analysis revealed that it should be highly positive to the correlation coefficients of mercury and arsenic in the fly ash and those of the flue gas emitted from medium size MSWIs. As it were, the concentrations of mercury and arsenic of flue gas from medium size MSWIs are high unless mercury and arsenic in fly ash are properly controlled in dust collection step in medium size MSWIs. It was also concluded that mercury, lead, arsenic, and selenium from MSWIs stacks could be controlled by waste heat boiler(WHE) and dust collecting step in medium size MSWIs.

• Journal of Preventive Medicine and Public Health
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• 제39권6호
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• pp.462-468
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• 2006

Objectives : The purpose of this study was to gain an understanding of the effects of three exercise types on anthropometric and serum lipids and physiological index factors, which are known to be the three risk factors of cardiovascular disease in male workers. Methods : The experimental study period was 12 weeks. In this study, 30-40's males (N=31) were assigned to 3 experimental groups: regular aerobic(treadmill walking) exercise group, regular anaerobic(muscular endurance) exercise group, irregular aerobic & anaerobic exercise group and a control group using a stratified random assignment method. Results : In relation to anthropometric factors, the regular aerobic & anaerobic exercise groups showed significant decreases in Weight, Broca's index, WC, BMI, WHtR, WHpR and HRrest. With regard to the serum lipid factors, the TC was decreased, but the HDL-c increased among the regular aerobic & anaerobic exercise groups. However, no significant difference was found between the other groups in respect to the LDL-c and TG. Considering the physiological factors, the TC/HD-c, TC-HDL/HDL-c, LDL-C/HDL-c and NON-HDL-c ratios were decreased, but the HDL-c/TC ratio increased among the regular aerobic & anaerobic exercise groups. The TG/HDL-c and HDL-c/LDL-c ratios showed no significant differences between the groups. These results indicated that the positive change for each factor is much larger in the regular exercise groups, especially in the anaerobic exercise group. Conclusions : The results indicate that not only regular aerobic exercise, but also regular anaerobic(muscular endurance) exercise could be utilized in lessening the deleterious effects of the risk index factors for cardiovascular disease.

• 한방재활의학과학회지
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• 제26권1호
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• pp.103-111
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• 2016

Objectives The waist circumference has been known as an obesity index reflecting the visceral fat. This study was conducted to investigate the obesity index of what can be predicted visceral fat obesity. Methods 121 test subjects who have $BMI{\geq}30$ or BMI 27~29.9 with having more than one high blood pressure, diabetes, and hyperlipidemia were gathered in the Gachon University Korean medical hospital. The relationship between obesity index, the abdominal fat area, and the metabolic syndrome component analyzed using Pearson correlation analysis. The obesity indices, that are largely used in clinics such as waist circumference (WC), HC (hip circumference), body mass index (BMI), waist-hip ratio (WHR) and waist-height ratio (WHtR). Total fat area (TFA), visceral fat area (VFA), subcutaneous area (SFA) and visceral fat/subcutaneous fat ratio (VSR) that was measured from CT. Results 1. Total fat area (TFA) was positively correlated WC, BMI, HC. 2. The subcutaneous fat area (SFA) was positively correlated HC, WC, BMI. 3. The visceral fat area (VFA) did not show a strong correlation with obesity indicators. Conclusions It was found indices of obesity and visceral fat area is a high correlation. BMI, WC was the obesity index showed a high correlation as the SFA, TFA.

• 한국통신학회논문지
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• 제15권3호
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• pp.221-231
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• 1990

본 논문에서는 예측오차의 분포와 비트할당표를 이용하여 계산량을 줄이는 방법으로 직접 2차원 WHT를 계산한 다음 상수행렬을 곱함으로써 2차원 DCT 를 계산하는 방법을 제안하였다. 이 2차원 고속 DCT 알고리즘은 곱셈이 마지막 단계에 집중되어 있으며, 따라서 변환계수 중에서 양자화 과정에서 제외되는 변환계수의 수에 비례하여 계산량을 줄일 수 있는 특징이 있다. 계산량 비교를 위하여, 예측오차에 대한 비교할당표에 할당된 DCT계수만을 구하고자 할 때의 계산량을 산출한 결과, 제안한 방식은 변환부호화에 할당된 화소당 평균 비트율이 0.6비트 이하일 때, 기존의 알고리즘 중에서 가장 계산량이 적은 고속 DCT 알고리즘 보다 계산량이 적게 되어, 변환부호화의 계산량 감축에 기여할 수 있음을 확인하였다.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.153-162
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• 2016

본 연구는 일반 성인을 대상으로 대사증후군 위험인자의 유병률을 파악하고, 각 대사증후군 위험인자들과 비만지표들과의 관련성을 파악하며, 비만지표들의 대사증후군을 예측하기 위한 관련성과 타당도를 검토하고자 시도하였다. 조사대상은 2014년 2월부터 11월까지의 기간에 한국건강관리협회 D지부 건강검진센타에서 종합건강검진을 받았던 20세 이상 1,051명을 대상으로 하였다. 연구결과, 조사대상자의 대사증후군 유병률은 21.5%이었으며, 각 위험인자의 유병률은 허리둘레의 경우 남자 31.8%, 여자 41.6%이었으며, TG는 남자 35.6%, 여자 17.3%이었고, HDL-C는 남자 17.6%, 여자 34.2%이었다. 혈압은 남자 53.5%, 여자 35.9%이었으며, FBS는 남자 14.9%, 여자 6.8%이었다. 이 같은 유병률은 연령이 높은 군일수록, BMI가 높은 군일수록, 음주횟수가 많은 군일수록, 유의하게 높았다. 비만지표별 대사증후군 위험요인 개수별 예측도를 보면 허리둘레/신장비가 높게 나타났다. 이상과 같은 결과를 볼 때, 다른 비만지표에 비해 허리둘레/신장비가 대사증후군 위험요인을 선별하는데 좀 더 예측력이 있다고 나타났다. 허리둘레/신장비는 간단하고 실용적인 복부비만의 지표가 될 수 있으며 대사증후군에 대한 선별검사로서 체질량지수와 허리둘레보다 우수한 것으로 나타났다.