• ETRI Journal
• /
• 제34권2호
• /
• pp.190-198
• /
• 2012

An adaptive correlation noise model (CNM) construction algorithm is proposed in this paper to increase the efficiency of parity bits for correcting errors of the side information in transform domain Wyner-Ziv (WZ) video coding. The proposed algorithm introduces two techniques to improve the accuracy of the CNM. First, it calculates the mean of direct current (DC) coefficients of the original WZ frame at the encoder and uses it to assist the decoder to calculate the CNM parameters. Second, by considering the statistical property of the transform domain correlation noise and the motion characteristic of the frame, the algorithm adaptively models the DC coefficients of the correlation noise with the Gaussian distribution for the low motion frames and the Laplacian distribution for the high motion frames, respectively. With these techniques, the proposed algorithm is able to make a more accurate approximation to the real distribution of the correlation noise at the expense of a very slight increment to the coding complexity. The simulation results show that the proposed algorithm can improve the average peak signal-to-noise ratio of the decoded WZ frames by 0.5 dB to 1.5 dB.

• 대한기계학회논문집B
• /
• 제24권6호
• /
• pp.760-768
• /
• 2000

Filter efficiency of electrically charged particle in uncharged fibrous filter was measured. In previous studies, the effect of charged particle on filter efficiency was investigated but there was difficulty in measuring of image effect that is appeared at the charged small particle. We could easily measure the image effect with charging small particles by photoelectric charging. The spark discharge aerosol generator and a differential mobility analyzer (DMA) were used to generate sub-micron monodisperse particles (${\leq}200$ nm). The generated particles were charged in photoelectric charging process using ultraviolet lamp and electric field. The filter efficiency of the charged particles, classified by another DMA, was measured in filter tester using a condensation nucleus counter (CNC) as function of particle diameter, particle charge and airflow velocity. It is shown that the filter efficiency increases with increasing charge number of the particle and is affected by particle size and flow velocity. Single fiber filter efficiency mainly depends on image force parameter and peclet number. The peclet number was not considered at previous other papers. We propose a modi fied experimental correlation as function of image force parameter and peclet number.

• 한국임상수의학회지
• /
• 제21권2호
• /
• pp.115-121
• /
• 2004

The purpose of this study was to ascertain the breeding efficiency in Thoroughbred mare. A total of 106 mares were investigated for the status of follicle (462 cases), ovulation (179 cases) and pregnancy (346 cases). Of total examination, 46.8% was follicle measure to determine breeding time, and mating rate per cases examined was 39.9%. There was no correlation between reproductive results and size of follicles or endometrial edema or degrees of teasing alone. 143 cases were ovulated among 179 cases which were performed ovulation examination, and ovulation rate and fertilization rate per mating times were 79.9% and 39.0%, respectively. The use of hCG(human chorionic gonadotropin), to facilitate ovulation, presented to increase occurrence of double ovulations and twin fertilizations In conclusion, though more examination to estimate the optimal breeding time and higher mating rate was performed, fertilization rate per mating times was lower and then reproductive efficiency also became decreased. Therefore, it seemed that accurate examination of reproductive tracks, appropriate teasing programme and hCG administration before ovulation were of help to improve ovulation rate and fertilization rate.

• 한국환경보건학회지
• /
• 제18권2호
• /
• pp.62-66
• /
• 1992

This study was performed to investigate the characteristics of livestock wastewater excepting pig feces and the variation tendency of water quality and the removal efficiency of polluting materials by establishing the sequencing batch reactor in the field.The results were as follows, 1. The characteristics of livestock wastewater as follows: BOD: 619.80, COD$_{cr}$: 782.70, NH$_{3}$-N: 194.20, TKN: 232.81, PO$_{4}$-P: 24.10, T-P: 215.14 (mg/l) 2. During the reaction, negative correlation existed between pH and dissolved oxygen concentration. 3. The removal efficiency of the organic material by the index of BOD and COD was about 90%. 4. Nitrogen removal efficiency was 65.6% by total Kjeldahl nitrogen index, and phosphorous removal efficiency was about 47% by PO$_{4}$-P concentration.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제13권2호
• /
• pp.83-88
• /
• 2005

This study investigates the air leakage and heat transfer characteristics of a commercially available rotary-type air-to-air heat exchanger with a fiber polyester matrix. Crossover leakage between the exhaust and supply air is measured using a tracer gas method for various ventilation rates and rotational speeds of the wheel. A correlation equation for the leakage is obtained by summing up pressure leakage and carryover leakage. The pressure leakage is observed to be a function of ventilation rate only, and the carryover leakage is found to be a linear function of wheel speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiency by taking into account the leakage ratio. The heat recovery efficiency decreases, as the ventilation rate increases. As the wheel speed increases, however, the efficiency increases initially but reaches a constant value for the speeds over 10rpm.

• 전기전자학회논문지
• /
• 제23권2호
• /
• pp.350-357
• /
• 2019

본 연구에서는 전체 태양광발전소의 80%를 차지하고 있는 소규모 태양광발전소의 에너지저장장치 연계에 따른 시스템 효율을 분석하였다. 설치용량이 100kW인 태양광발전소의 데이터를 수집하고 각 발전소의 PCS와 배터리의 용량에 따른 ESS 효율의 상관관계를 도출하였으며 결론적으로 배터리의 방전속도에 영향을 미치는 C-Rate의 수치가 높을수록 ESS의 방전효율이 높아지는 것으로 나타난다.

• Archives of Metallurgy and Materials
• /
• 제66권3호
• /
• pp.689-693
• /
• 2021

In this study, we propose a cooling structure manufactured using a specialized three-dimensional (3D) printing design method. A cooling performance test system with complex geometry that used a thermoelectric module was manufactured using metal 3D printing. A test model was constructed by applying additive manufacturing simulation and computational fluid analysis techniques, and the correlation between each element and cooling efficiency was examined. In this study, the evaluation was conducted using a thermoelectric module base cooling efficiency measurement system. The contents were compared and analyzed by predicting the manufacturing possibility and cooling efficiency, through additive manufacturing simulation and computational fluid analysis techniques, respectively.

• 한국치위생학회지
• /
• 제6권2호
• /
• pp.129-141
• /
• 2006

This study attempts to provide basic information that is necessary to establish the direction of oral health education process abd to develop effective oral health promoting programs for college students by analyzing the modifying factors that may affect their oral health behaviors and their cognitive and perceptive factors. Data for this study are collected by the questionnaire method from college students who attend colleges located Chungchong and Busan province for the period between June 20, 2006 and July 30, 2006. The respondents were chosen from Dental department and Non-Dental department. After omitting the responses with insufficient information, 409 valid responses are used for this analysis. The major finding of the present study are as follows: 1. Oral health behaviors factor is higher rate dental department than non-dental department, dental department than non-dental department appear significant the oral health education, the lasted year round oral examination, the used of oral hygiene supplies, oral prevention treatment. 2. Oral health behaviors and perception-awareness factor is higher score dental department than non-dental department and self efficiency is similar. Oral health behaviors is higher score dental department, the barriers to oral health behaviors is similar. The benefits of oral health behavior is higher score dental department. 3. The oral health behavior is higher dental department. In dental department the overall average score for oral health behaviors question is the correct teeth-brushing, self-restraint of liquor and cigarettes. Non dental department the overall average score for oral health behaviors question is the correct teeth brushing, good nutrition. The lower average score is scaling and periodic oral examination. 4. The correlation coefficient analysis between oral health behaviors and perception-awareness factors, variables which appear significant correlation coefficient by the self-efficiency are the control of oral health, the benefits of oral health behaviors, behavior of oral health, variables which appear significant correlation coefficient by the control of oral health are the benefits of oral health behaviors, the knowledge of oral health, behavior of oral health. And variables which appear significant correlation coefficient by the barriers to oral health behaviors is the benefits of oral health behaviors, variables which appear significant correlation coefficient by the knowledge of oral health is oral health behaviors.

• 한국도로학회논문집
• /
• 제17권4호
• /
• pp.135-141
• /
• 2015

PURPOSES: This study has been conducted to determine a homogeneous segment and integration to improve the efficiency of short-term traffic count. We have also attempted to reduce the traffic monitoring budget. METHODS: Based on the statistical approach, a homogeneous segment in the same road section is determined. Statistical analysis using t-test, mean difference, and correlation coefficient are carried out for 10-year-long (2004-2013) short-term count traffic data and the MAPE of fresh data (2014) are evaluated. The correlation coefficient represents a trend in traffic count, while the mean difference and t-score represent an average traffic count. RESULTS : The statistical analysis suggests that the number of target segments varies with the criteria. The correlation coefficient of more than 30% of the adjacent segment is higher than 0.8. A mean difference of 36.2% and t-score of 19.5% for adjacent segments are below 20% and 2.8, respectively. According to the effectiveness analysis, the integration criteria of the mean difference have a higher effect as compared to the t-score criteria. Thus, the mean difference represents a traffic volume similarity. CONCLUSIONS : The integration of 47 road segments from 882 adjacent road segments indicate 8.87% of MAPE, which is within an acceptable range. It can reduce the traffic monitoring budget and increase the count to improve an accuracy of traffic volume estimation.

• 한국통신학회논문지
• /
• 제36권12C호
• /
• pp.721-726
• /
• 2011

차세대 비디오 압축 표준으로 현재 개발 중인 HEVC(high efficiency video coding)는 기존 비디오 압축 표준인 H.264/AVC에 비해 40% 정도의 성능 향상을 보인다. 기존의 양안식 영상을 부호화하기 위한 코텍은 H.264/AVC 기반으로 제작되었기 때문에, HEVC를 이용하여 양안식 영상을 부호화 하면 성능 향상을 기대할 수 있다. 또한 양안식 영상은 기존의 각 화면의 시간 상관도{temporal correlation)에 더해서 화면간의 상관도(interview correlation)가 존재하기 때문에, 좌우 영상을 함께 부호화하는 것이 성능 개선에 유리하다. 본 논문에서는 HEVC의 참조 소프트웨어인 HM 3.4를 이용하여 화면간의 상관도를 고려한 양안식 영상 부호화 방법을 제안한다. 화면간의 예측을 이용한 제안한 코텍을 이용해 부호화한 오른쪽 영상과 기존 HEVC로의 오른쪽 화면을 부호화했을 때의 성능을 비교한 결과 BDBR이 약 36.24% 감소했으며 BDPSNR은 1.19 dB가 증가했다.