• 제목/요약/키워드: Intake Part

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조합형 소음기를 이용한 육상발전용 디젤 엔진의 흡기 소음 제어 (Intake Noise Control of Diesel Power Plant using Combined Silencer)

  • 송근복;주원호;김동해
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
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    • pp.861-866
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    • 2012
  • Turbo-charger noise radiated from air intake part is one of the most important noise sources in diesel power plant. In this paper, intake noise control of the diesel power plant was studied using parallel baffle type silencer and concentric hole-cavity resonator simultaneously. Firstly, acoustical characteristics and attenuation performance for parallel baffle type silencer were investigated through theoretical approach and experimental method. Based on the results, optimal design of the parallel baffle silencer was suggested. Secondly, for reducing the low frequency noise contained in the intake noise, the concentric hole-type resonator was developed and the acoustic performance was verified from the test. By combining two types of silencers, it is expected that the overall insertion loss is about 50 dB. So, the combined silencer is very helpful in reducing the intake noise of diesel power plant.

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Dietary Intake of Korean Adults Is Not Significantly Affected by Sleep Duration

  • Kim, Young-Ok
    • Preventive Nutrition and Food Science
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    • 제8권4호
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    • pp.395-400
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    • 2003
  • This study investigated the effect of sleep duration on food and nutrient intake among adult Koreans. The effects of sleep duration on dietary patterns was studied in 7,370 Korean adults, aged 20 and older, who participated in the 1998 Korean National Health and Nutrition Survey in which the 24 hour recall method was used to estimate dietary intake. Sleep duration data from individual subject were collected by interview as a part of a behavior survey. Analysis of variance and Duncan's multiple range test were used to test the differences in food and nutrition intake and sleep duration. Food intakes of the male subjects were not significantly different among three groups. However, there were significant differences observed in intakes of beverage and alcohol among female subjects among the three groups. There were no significant differences observed for nutrient intake by sleep duration for either gender. Unlike the observation from European and American studies, food and nutrient intake of Korean subjects, in general, were not greatly affected by duration of sleep. This result may suggest that dietary habits of Koreans, as affected by sleep, are quite different from those of Europeans & Americans.

Seismic risk assessment of intake tower in Korea using updated fragility by Bayesian inference

  • Alam, Jahangir;Kim, Dookie;Choi, Byounghan
    • Structural Engineering and Mechanics
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    • 제69권3호
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    • pp.317-326
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    • 2019
  • This research aims to assess the tight seismic risk curve of the intake tower at Geumgwang reservoir by considering the recorded historical earthquake data in the Korean Peninsula. The seismic fragility, a significant part of risk assessment, is updated by using Bayesian inference to consider the uncertainties and computational efficiency. The reservoir is one of the largest reservoirs in Korea for the supply of agricultural water. The intake tower controls the release of water from the reservoir. The seismic risk assessment of the intake tower plays an important role in the risk management of the reservoir. Site-specific seismic hazard is computed based on the four different seismic source maps of Korea. Probabilistic Seismic Hazard Analysis (PSHA) method is used to estimate the annual exceedance rate of hazard for corresponding Peak Ground Acceleration (PGA). Hazard deaggregation is shown at two customary hazard levels. Multiple dynamic analyses and a nonlinear static pushover analysis are performed for deriving fragility parameters. Thereafter, Bayesian inference with Markov Chain Monte Carlo (MCMC) is used to update the fragility parameters by integrating the results of the analyses. This study proves to reduce the uncertainties associated with fragility and risk curve, and to increase significant statistical and computational efficiency. The range of seismic risk curve of the intake tower is extracted for the reservoir site by considering four different source models and updated fragility function, which can be effectively used for the risk management and mitigation of reservoir.

Effect of the Intake Valve Opening Timings and Fuel Injection Pressures on the Exhaust Emission Characteristics of a Gasoline Engine at Part Load Condition

  • Lee, Hyung-Min;Jeong, Yeon-Hwan
    • Journal of Advanced Marine Engineering and Technology
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    • 제35권3호
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    • pp.317-322
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    • 2011
  • This work has investigated the exhaust emissions such as Total Hydrocarbon (THC), Nitrogen Oxides(NOx), and Particulate Matter (PM) characteristics emitted from the tail-pipe of a continuously variable valve timing (CVVT) gasoline-fueled engine with different intake valve opening timings and injection pressures at the part load condition. Valve overlap period was varied from $40^{\circ}CA$ to $10^{\circ}CA$ and fuel injection pressure was increased from 3.5 bar to 5.0 bar. THC and NOx emissions decreased as intake valve opening timing was advanced regardless of fuel injection pressure. When the fuel was injected with the condition of 5.0 bar at all of valve overlap ranges, THC levels were reduced by 55%. NOx concentrations were diminished about 75% as valve overlap increased. PM size distributions were analyzed as bi-modal type of the nucleation and accumulation mode. Comparing with fuel injection pressures, PM emission levels were decreased at high pressure injection of 5.0 bar condition.

Factors associated with low water intake among South Korean adolescents - Korea National Health and Nutrition Examination Survey, 2007-2010

  • Lee, Haeng-Shin;Park, Sohyun;Kim, Mi-Hyun
    • Nutrition Research and Practice
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    • 제8권1호
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    • pp.74-80
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    • 2014
  • Water is essential for life and plain water instead of sugar-sweetened beverages is one approach for decreasing energy intake. Due to limited data on characteristics associated with water intake among Korean adolescents, this study examined associations of demographic and behavioral characteristics with plain water intake by using nationally representative sample of South Korean adolescents. The data (2007-2010 Korea National Health and Nutrition Examination Survey) for 1,288 high school-aged adolescents (15-18 years) were used. Multivariable logistic regression was used to calculate adjusted odds ratios (OR) for factors associated with low water intake (< 4 cups/day) and very low water intake (< 2.5 cups/day). Nationwide, 38.4% and 19.0% of adolescents reported drinking water < 4.0 cups/day and < 2.5 cups/day, respectively. The mean plain water intake was 5.7 cups/day for males and 4.1 cups/day for females. Females had significantly higher odds for drinking water < 2.5 cups/day (OR = 2.2) than males, whereas adolescents with low milk consumption had significantly lower odds for drinking water < 2.5 cups/day (OR = 0.7). Factors significantly associated with a greater odds for drinking water < 4 cups/daywere being female (OR = 2.8) and not meeting physical activity recommendations (${\geq}20$ min/day on < 3 days/week) (OR = 1.6). Being underweight, overweight, and obese were significantly associated with reduced odds for drinking water < 4 cups/day (OR = 0.7, 0.4 and 0.5, respectively). However, intake of soda, coffee drinks, fruits, vegetables, and sodium and eating out were not significantly associated with low or very low water intake. These findings may be used to target intervention efforts to increase plain water intake as part of a healty lifestyle.

특수지역(特殊地域)의 영양섭취(營養攝取) 상태조사(狀態調査) -제이보(第二報) 승려(남승, 여승)에 대하여- (Nutrition Survey for Special Groups -Part II : For Buddhists (male, female)-)

  • 유덕자;박춘자;유정열
    • Journal of Nutrition and Health
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    • 제2권4호
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    • pp.183-185
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    • 1969
  • Following the previous report (Part I: For Sea-divers and Hwa-Jeon-Min) authers have conducted another nutrition survey for Buddhists (male and female) in a temple 'Soo Duk Sa' locating in ChungNam province. The following results were obtained: 1. Cereals, green vegetables and potatoes were staple foods for the Buddhists (male and female) and no any animal foods were eaten by them during the survey period. 2. Carbohydrate intake was very high and the calorie derived from it occupied approximately 80% of tatal calorie intaken. 3. All the nutrients except carotene, niacin and iron are low in their amounts of intake. Especially, protein and riboflavin intakes are low. 4. Buddhists are prohibited to eat animal foods. Therefore, nutrition education and guidance are needed for them to supplement the protein and some other problems.

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보건소 노인 영양 개선 사업 : 영양밀도와 섭취 식품군의 다양성에 의한 노인 영양 평가 (Elderly Nutrition Improvement Program in the community health center : Nutritional evaluation of the elderly using the Index of Nutritional Quality and food group intake pattern)

  • 임경숙
    • 대한영양사협회학술지
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    • 제3권2호
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    • pp.182-196
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    • 1997
  • Physiological changes that affect nutrient absorption and utilization occur in older adults, and the collection of nutritional information is an important part of examining the nutrition and health issue. A nutritional survey using the 24-hour recall method was performed to identify nutritional quality and leading patterns of food group intake for protein, vitamin C, P and Fe were over 1, whereas those for vitamin A, $B_1$, $B_2$, niacin and Ca were below 1. The MAR(Mean Adequacy Ratio) was relatively low(0.75). The percentage of energy from carbohydrate, protein, and fat was 65.1, 15.6, and 19.5, respectively, thus the quantities of energy source were ideal. The Older subjects revealed poorer nutrition quality than the younger subjects did. The food group intake pattern of the elderly was not diverse, only 9% of them consumed all food groups in a day. These results suggest that nutritional guidelines for older Koreans should focus on the maintenance of adequate energy intake. In addition, selection of foods with high protein and calcium, such as dairy food, should be emphasized, particularly in the older elderly. Nutrition programs should target individuals at risk of not receiving enough nutrients, like the oldest elderly, and persons with lower education.

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일 지역 중국인 유학생의 영양소 섭취 상태, 체질량지수와 우울의 관계 (Nutritional Intake, Body Mass Index and Depression Among Chinese College Students in an Urban Area of South Korea)

  • 진정;서민희
    • Journal of Korean Biological Nursing Science
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    • 제22권2호
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    • pp.81-89
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    • 2020
  • Purpose: The purpose of this study was to investigate nutritional intake, body mass index (BMI) and depression, and to elucidate depression in relation to nutritional intake and BMI among Chinese college students studying in South Korea. Methods: A descriptive study design was adopted. Data were collected from 170 Chinese college students in South Korea June-August, 2019. In this study, 24-hour dietary records were obtained and BMI was measured. Nutrient intakes were calculated from the dietary records using the CAN-PRO software. Depression was assessed using the Center for Epidemiological Studies Depression Scale (CES-D). Results: Of 170 participants, 19 (11.2%) were underweight and 42 (24.7%) were overweight. Female, single, and non-smoking participants were underweight. There were 97 (57.1%) participants experiencing depression, and 99 (58.2%) consuming lower protein than the recommended nutrient intake resulting in insufficient nutrients. The intake of vitamin A, vitamin C, vitamin D, pantothenic acid, calcium, iron, and selenium was much lower than the standard. Depressive participants were significantly greater among the underweight participants and those consuming insufficient nutrients in terms of protein, pantothenic acid, and selenium. Conclusion: An intervention program is required to improve nutritional status, which should be a part of the strategies to manage depression for Chinese college students in South Korea.

열가소성 플라스틱 흡기 터보차져호스의 설계 변수에 따른 차량 실내 소음에 미치는 영향에 관한 연구 (A study on influence of vehicle interior noise according to design parameters of thermoplastic turbo charger intake hose)

  • 진용선;윤지용;이춘수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
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    • pp.367-368
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    • 2012
  • In resent years, engineering thermoplastics represent a means for designers to integrate parts, facilitate assembly, reduce weight and lower the costs of their parts to improve the fuel efficiency and competitiveness of the cars. Thermoplastic turbo charger intake hose is one of most sophisticated application in thermoplastics under the hood. Used as part of weight & cost reduction and performance improvement program, thermoplastic turbo charger intake hose has been developed as rubber and metal replacement. For optimized product, NVH performance is a important criteria while keeping same durability required with current system. Though a number of studies have been conducted on the resonator hose and its analytical models, the most of studies were focused on transmission loss itself. This paper presents contribution of vehicle interior noise according to design parameters like profile, bellows type, bellows position, material characteristic. And we will review the design guidance for optimized product of thermoplastic turbo charger intake hose.

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