• Title/Summary/Keyword: Head Distribution

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A Study on the Effect of Sweep Angle of Axial Fan on Its Noise (축류송풍기의 스윕각이 소음에 미치는 영향에 대한 연구)

  • Choi, Jae-Ho;Kim, Kwang-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.365-370
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    • 2000
  • A computational study on the effect of sweep angle of axial fan on its noise is performed in the present paper. The forward swept axial fan was designed by numerical optimization method incorporated with three dimensional flow analysis. The objective function was defined by the ratio of generation rate of turbulent kinetic energy to pressure head. And, two variables related with sweep angle distribution are used for design variables. The swept fan has better performance characteristics and noise level. The experimental result shows that spectrums of no-sweet and swept fans have differences in the blade passage frequency, especially in the broadband. And the overall noise level of swept fan is lower 10dB(A) than that of no-sweep fan. For the comparison of flow fields between no-sweep fan and swept fan, CFX-TASCflow computational fluid dynamics software is used. Standard k-${\varepsilon}$ model is used for the turbulence model. Distributions of pressure and turbulent kinetic energy distributions are compared in order to find what happen in the low-noise swept fan.

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Microwave Drying of Persimmon Lumbers for Golf Club Head (I) - Drying Curves and Temperature Distribution of 30mm Thick Lumbers - (Golf Club Head용 감나무재의 Microwave 건조 (I) - 30mm 판재의 건조경과와 온도변화 -)

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.1
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    • pp.35-41
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    • 1995
  • Persimmon boards of 30mm thick were dried, their temperatures were monitored during drying with 490 and 200watt microwave, and the drying efficacy and problems were investigated. The effects of pretreatments such as presteaming and prefreezing were also examined. The persimmon green lumbers of 80% moisture content were dried to 10% for only 50~60 and 110 minutes with 49watt and 200watt microwave, respectively. Severe internal checks were, however, found in all boards. The presteamed boards collapsed on their surfaces earlier than the controls. It may attribute to the high temperature inside boards during microwave drying and the decrease of their internal tensile strength caused by the presteaming treatment. To increase the internal tensile strength of the pretreated boards and to reduce their internal checks, they were air-dried at room temperature. The air-dried boards could be dried to 10% moisture content clearly and free from defects with 200watt microwave. The heating efficiency were also calculated with the maximum weight loss per minute of 490watt and 200watt.

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Properties of Porous SiC Ceramics Prepared by Wood Template Method

  • Ha, Jung-Soo;Lim, Byong-Gu;Doh, Geum-Hyun;Kang, In-Aeh;Kim, Chang-Sam
    • Journal of the Korean Ceramic Society
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    • v.47 no.4
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    • pp.308-311
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    • 2010
  • Porous SiC samples were prepared with three types of wood (poplar, pine, big cone pine) by simply embedding the wood charcoal in a powder mixture of Si and $SiO_2$ at 1600 and $1700^{\circ}C$. The basic engineering properties such as density, porosity, pore size and distribution, and strength were characterized. The samples showed full conversion to mostly $\beta$-SiC with good retention of the cellular structure of the original wood. More rigid SiC struts were developed for $1700^{\circ}C$. They showed similar bulk density ($0.5{\sim}0.6\;g/cm^3$) and porosity (81~84%) irrespective of the type of wood. The poplar sample showed three pore sizes (1, 8, $60\;{\mu}m$) with a main size of $60\;{\mu}m$. The pine sample showed a single pore size ($20\;{\mu}m$). The big cone pine sample showed two pore sizes (10, $80\;{\mu}m$) with a main size of $10\;{\mu}m$. The bend strength was 2.5 MPa for poplar, 5.7 MPa for pine, 2.8 MPa for big cone pine, indicating higher strength with pine.

A Study on Design Techniques for Span Length and Guy Wire Strength in Straight Over-head Distribution Lines (직선 가공배전선로 경간 및 지선강도 설계방안 연구)

  • Wong, Yoon-Chan;Sun, Sang-Jin;Kim, Sang-Kyu;Kim, Chang-Wan
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2226-2227
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    • 2008
  • 가공배전선로는 태풍과 같은 자연재해에 상시 노출되어 시설되므로 전기고장 및 설비피해가 발생할 우려가 매우 높다. 그러나 이와 관련한 실질적인 연구들이 부족하여 가공배전선로의 설계원들이 직선선로의 경간 결정시 단순히 저압부하밀도 및 전주강도만을 고려하고 있으며, 인류지선 및 종지선의 규격 선정방법을 잘 이해하지 못함에 따라 규격 선정의 오류가 발생되기도 한다. 따라서 본 고에서는 그 동안의 연구결과를 바탕으로 가공배전선로 설계시 수평선간이격거리를 고려한 경간 결정방법과 장경간 및 표준경간의 인류지선, 장경간개소 종지선 결정방법에 대하여 사례를 통해서 설명하였다. 본 고에서 제시한 방법에 따라 설계검토를 시행한다면 표준경간에서 선간단락고장을 예방할 수 있을 뿐만 아니라, 장경간 및 표준경간의 인류지선 및 종지선의 강도가 재해시에도 충분한 강도를 확보하여 설비피해 및 전기고장을 예방할 수 있을 것으로 기대된다.

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Changes in Space Norms and Related Factors of Households in Ulsan, Korea (울산시 거주 가구의 공간규범 변화 특성과 관련요인 분석)

  • Yang, Sehwa;Ryu, Hyunjoo
    • Human Ecology Research
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    • v.52 no.2
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    • pp.165-173
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    • 2014
  • The study was conducted to analyze whether the recent trends in preference toward small and medium-sized housing in Korea represent changes in space norms. To accomplish this, the existing data from Statistics Korea and two different empirical data sets collected in 2007 and 2012 from Ulsan, Korea, were statistically analyzed through descriptive statistics, cross-tabulation analysis with a chi-squared test and multiple regression analysis. In the analyses, the space norms of households were compared and any changes in the space norms and the related factors were determined. The space norms were mainly investigated in terms of the housing size and the number of rooms. The results are as follows: 1) since 2010, there have been changes in the housing stock distribution in terms of size. Stocks of small housing increased, while those of medium and large housing decreased. Nevertheless, the overall conditions of spatial density have improved considerably in the recent 30 years. 2) It was found that there were statistically significant differences between 2007 and 2012 in space norms. The norms for housing sized less than 99 m2 and with one or two rooms were found to have increased, while that for housing sized more than 132 m2 decreased. 3) Household size, education of the head, monthly household income, housing type and the number of bedrooms in the current dwelling were the significant explanatory variables of space norms.

A Study on Wi Syndrome(痿證) in "Hwangjenaegyeong(黃帝內經).Wiron(痿論)" ("황제내경(黃帝內經).위론(痿論)"의 위증(痿證)에 대한 고찰(考察))

  • Baek, Yu-Sang
    • Journal of Korean Medical classics
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    • v.23 no.1
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    • pp.1-10
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    • 2010
  • Wi Syndrome(痿證) mainly occurs from fluid damages[津液損傷] caused by heat in Gi(氣) phase of the Five viscera, while it sometimes come from the outside. Although the symptoms are presented in the limbs, the disorder roots in the Five viscera, most deeply located in the human body, Therefore, to approach the disorder, we must apply differentiation of the Five viscera in diagnosis. The Lungs, as the head of the Five viscera control the production and distribution of bodily fluids in the body. Functional disorder of the Lungs bring about Wi Syndrome regardless of it being in the Gi phase. Also, psychological depression leads to Wi Syndrome, In other words, depression and uneasiness easily results in the state of Gi blocking and fluid exhaustion in this modern society where there is less manual labor and excessive use of the brain. Besides Gi blockage, the top muscle[宗筋] theory is another important mechanism in the occurrence of Wi Syndrome. Moreover, the disorder is related to Yangmyeong(陽明), which is the sea of food, Chungmaek(衝脈) which is the sea of meridian, in addition to Immaek(任脈), Dokmeak (督脈) and Deameak(帶脈) which are all involved in Wi Syndrome. In conclusion, the Wi Syndrome happens when various factors involved lose balance and harmony with each other.

The Clinical Study of Atopic Dermatitis (아토피 피부염(皮膚炎) 환자(患者) 67명(名)에 대(對)한 임상적(臨床的) 고찰(考察))

  • Lee Jin-Yong;Kim Deok-Gon
    • The Journal of Pediatrics of Korean Medicine
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    • v.13 no.2
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    • pp.171-186
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    • 1999
  • Atopic dermatitis is a chronic or chronically relapsing, pruritic dermatitis. It commonly occurs in patients with a personal or family history of atopy. We studied 67 children suffering from atopic dermatitis Oriental Medicine Hospital in Kyunghee University, and analyzed sex, age, feeding, clinical manifestation, risk factor. The results were as follows : 1.Most age distribution of children was from 2 to 6, male to female ratio was 1:1.03 2.Breast-feeding to milk-feeding ratio was 2.93:1 3.Frequency of aggravating symptom by specific food was 31.3%, among this, meat(especially chicken) was revealed high risk factor 4.Frequency of family history suffering from other allergic disease was 61.2%, among this father to mother ratio was 1.27:1 5.Sites of atopic dermatitis were as follows : The inner space of elbow and knee joint was 77.65, back, face, neck was 56.7%, back of ear was 52.2%, wrist was 46.3%, abdomen was 38.8%, ankle was 34.3%,head was 29.9%.

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Most to Least Preferred Parameters Affecting the Quality of Education: Faculty Perspectives in India

  • Kumari, Neeraj
    • The Journal of Asian Finance, Economics and Business
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    • v.1 no.3
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    • pp.37-42
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    • 2014
  • The objective of the study is to find out the faculty members' perspective of most and least preferred parameters affecting the quality of education in an affiliated undergraduate engineering institution in Haryana, India. It is a descriptive research. The data has been collected with the help of Questionnaire Based Survey. The sample size for the study is 110. The respondents are the faculty members teaching B. Tech who were selected randomly from the above said geographical area. For data analysis and conclusion of the results of the survey, statistical tool like factor analysis was performed in SPSS. The most preferred aspects of the institution by the faculty members are: a secured Wi-Fi facility is well channelized to provide easy access, library is well equipped, faculty can visit the library with ease whenever they find time, toilets for the faculty are hygienic and in adequate number, parking facility for the faculty vehicle is spacious, adequate Industry Institute Interaction for the faculty development etc. The least preferred aspects of the institution by the faculty members are: faculty / staff rooms are spacious, well furnished and adequate in number, and working relationships between the Head of Departments and their faculty members are synchronized.

Citizen Awareness of the Smart City: A Study of Khon Kaen, Thailand

  • KAMNUANSILPA, Peerasit;LAOCHANKHAM, Sirisak;CRUMPTON, Charles David;DRAPER, John
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.7
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    • pp.497-508
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    • 2020
  • Using primary data collected through semi-structured interviews conducted during February 2019, this article examines citizen's awareness and knowledge of Khon Kaen Smart City (KKSC) among the residents of five contiguous municipalities within Khon Kaen Province, Thailand. A self-weighted sample of 420 respondents was selected through a two-stage, 30-cluster sampling process. In the first stage, a sample of 30 artificial clusters of 100 households each was selected. In the second, 14 households were randomly selected from each of these clusters. The head of household or, if unavailable, a resident aged 18 or over was interviewed. The study applies the "citizens as democratic participants" dimension of Simonofski et al.'s (2019) evaluative framework. Results found that, because of ineffective citizen engagement, the levels of awareness and knowledge about KKSC were low. However, multiple logistic regression found that, despite the low levels of awareness and knowledge, education and income could establish an independent effect on awareness of KKSC. Those who completed post-secondary school were more aware of KKSC than those who finished only secondary or primary education. Similarly, the analysis of data clearly indicated that educational attainment, solely and independently from all other socio-economic and demographic variables, could explain the positive effect of education on knowledge about KKSC.

Genetic Variation and Biological Control of Fusarium graminearum Isolated from Wheat in Assiut-Egypt

  • Mahmoud, Amer F.
    • The Plant Pathology Journal
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    • v.32 no.2
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    • pp.145-156
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    • 2016
  • Fusarium graminearum Schwabe causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss of wheat and other cereal crops. Twelve isolates of F. graminearum were collected from naturally infected spikes of wheat from Assiut Egypt. These isolates were compared using SRAP. The results indicated distinct genetic groups exist within F. graminearum, and demonstrated that these groups have different biological properties, especially with respect to their pathogenicity on wheat. There were biologically significant differences between the groups; with group (B) isolates being more aggressive towards wheat than groups (A) and (C). Furthermore, Trichoderma harzianum (Rifai) and Bacillus subtilis (Ehrenberg) which isolated from wheat kernels were screened for antagonistic activity against F. graminearum. They significantly reduced the growth of F. graminearum colonies in culture. In order to gain insight into biological control effect in situ, highly antagonistic isolates of T. harzianum and B. subtilis were selected, based on their in vitro effectiveness, for greenhouse test. It was revealed that T. harzianum and B. subtilis significantly reduced FHB severity. The obtained results indicated that T. harzianum and B. subtilis are very effective biocontrol agents that offer potential benefit in FHB and should be harnessed for further biocontrol applications. The accurate analysis of genetic variation and studies of population structures have significant implications for understanding the genetic traits and disease control programs in wheat. This is the first known report of the distribution and genetic variation of F. graminearum on wheat spikes in Assiut Egypt.