• 제목/요약/키워드: Limited Sound Level

검색결과 38건 처리시간 0.021초

과풍속 출력 제한형 소형 풍력 발전장치 개발 (Development of the Furling Control Type Small Wind Turbine System)

  • 최영철;김철호;이현채;서영택;한용운;송정일
    • 한국정밀공학회지
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    • 제29권6호
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    • pp.693-701
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    • 2012
  • In this study, a small wind turbine airfoil specialized for national wind condition was designed in order to develop the furling control type HAWT. And then a flow analysis was carried out based on the blade drawing which was designed to characterize of the developed airfoil. The result of the flow analysis showed that the torque on the 3 blades was 180.23N.m. This is equivalent to an output power of 5.66kw and an output efficiency of 0.44. Then we produced and constructed a 3kW - furling control type HAWT by getting the system unit design technology such as the specialized furling control device. By operating this turbine, we could get 3kW of the rated power at a wind speed of 10.5m/s through the ability test. Cut-in wind speed was 2m/s, generator efficiency was 92% at the rated power output. Sound power level was 87.2dB(A). Also we observed that the output power was limited to 10.5m/s with furling system operation.

밭토양에서 토양수분과 온도변화에 따른 분변성 대장균 사멸율 변화 (Pathogenic E. coli Inactivation in Upland Soils to a Change of Soil Moisture Content and Temperature)

  • 김민경;김민영;최철만;고병구;권순익;원항연
    • 한국토양비료학회지
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    • 제43권1호
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    • pp.90-95
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    • 2010
  • 전 세계적으로 가축분뇨를 농경지에 시용하는 것은 작물과 토양에 양분을 공급하는 측면에서 오래 전부터 이용되어 왔으며, 최근 들어서는 자원을 재순환하기 위한 측면으로 이용되고 있다. 그러나, 환경적인 측면에서 가축분뇨를 농경지에 시용하였을 때 미생물적 평가나 규제기준은 비용과 시간이 많이 요구되어 우리나라에서는 이에 대한 연구가 수행되지 못한 실정이다. 따라서, 본 연구는 밭토양에서 토양수분과 온도조건에 따른 분변성 대장균의 사멸율을 조사하여 분변성 대장균이 외부 환경에 영향을 미칠 수 있는 수준을 평가하고자 수행하였다. 시료는 토양수분조건(10, 35, 65, 80%) 및 온도조건 (20, 25, $30^{\circ}C$)별로 정해진 기간 (3, 7, 14, 21, 28일) 동안 배양되었으며 각각의 시료에 포함된 대장균의 수는 plating method 를 이용하여 측정되었다. 분산분석을 통한 측정자료의 통계분석 결과, 분변성 대장균의 생존에는 토양수분함량과 온도가 주 요인이었는데, 특히 토양수분함량이 감소할수록 그리고 온도가 증가할수록 E. coli의 사멸율은 직선적으로 증가하였다. 또한, 토양수분 조건과 온도조건 중에서 분변성 대장균의 사멸율은 온도조건에 더 상관이 높은 것으로 나타났으며, 모든 온도조건에서 10%의 토양수분조건에서 분변성 대장균의 사멸율이 높았다. 이는 토양수분이 E. coli의 사멸에 제한적인 요인으로 작용하였음을 의미한다. 따라서, 본 연구는 가축분뇨를 농경지에 시용할 때 인체의 위해성과 외부 환경의 건전성을 유지하기 위해서는 고온 저습한 토양조건에서 시용하여야 한다는 현실적인 가이드라인을 제시하고자 한다.

거리독립 해양환경에서 고속이동 음원의 고주파 잔향음 신호모의 (High-frequency Reverberation Simulation of High-speed Moving Source in Range-independent Ocean Environment)

  • 김선효;이원병;유승기;최지웅;김우식;박정수;박경주
    • 한국음향학회지
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    • 제32권2호
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    • pp.104-115
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    • 2013
  • 천해 환경에서 고주파 능동소나를 운용할 경우 각 경계면에서의 잔향음 및 도플러 효과는 소나 운용에 제한요소로 작용한다. 따라서 잔향음 제한 환경에서 소나 시스템을 운용하기 위해서는 그 환경 조건에서 발생하는 잔향음 준위를 예측하는 것이 중요하다. 본 논문에서는 거리 독립 환경에서 고속으로 이동하는 음원에서 수신되는 잔향음 신호를 모의할 수 있는 고주파 잔향음 모델을 제안한다. 본 모델에서는 음선 이론과 음선 송신각 최적화 방법을 이용하여 음원에서 각 경계면까지의 고유음선 정보를 계산하고, 이동하는 음원에 의해 변화된 음원 수신 위치는 음속 그리고 음원의 방향 및 속도를 고려한 산란경로 탐색 알고리즘에 의하여 계산된다. 또한 해수면 및 해저면에서의 산란 효과는 APL-UW 산란 모델을 적용하여 고려한다. 본 논문에서 제안한 잔향음 모델은 2010 년 8월 측정된 실험과 비교 검증된다. 본 논문에서 제안된 잔향음 모델은 잔향음 신호의 통계적 특성을 잘 반영하도록 개발되었다.

일부 공단 지역 가정 어머니의 식생활 관리 태도 비교 (Comparison of Meal Management Attitudes among Housewives between in Industrial Complex and in Non-Industrial Complex on Ansan City in Korea)

  • 남숙연;김선효
    • 대한가정학회지
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    • 제40권4호
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    • pp.167-178
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    • 2002
  • This study was carried out to compare the meal management attitudes among the mothers(41 years of age) who had middle school students between in industrial complex and in non-industrial complex. The subjects of each group were composed of 192 mothers Living in Ansan city in Korea, and this study was performed by self-administered questionnaire. The results of the present study were as follows: (1) Monthly family income and education level of parents were lower in industrial complex-family(ICF) than in non-industrial complex-family (NICF). The mean age of mothers and family size were similar in two groups, but the frequency of mothers employed was higher in ICF than in NICF Most mothers in ICF worked as a manual- or skilled-laborer. (2) The mothers in ICF tended to have less positive attitude in sewing balanced meals to their families than those in NICF. The score of nutritional knowledge was lower in mothers in ICF than those in NICF. (3) The percentage of expense for purchasing staple foods to total expense of foods tended to be higher in ICF than in NICF. Engel's coefficient was higher, and the frequency and expense for eating out was lower in ICF than in NICF (4) The mothers in ICF did not try to use their time and energy efficiently for meal management. (5) The mothers in ICF were less active in sewing the pleasurable meals including the provision of various cooking methods, flavors, and temperatures, to their families, than those in NICF. Above findings show that family environment such as industrial complex-families and non-industrial complex-families influences the meal management attitudes of mothers. The mothers in ICF had a less positive altitudes for scientific meal managements than those in NICF even though they had the limited resources including money, time and energy for meal management because most mothers in ICF had a job that were paid low salary and finished irregularly or late. Therefore, these results underscore the need to provide the sound nutritional education for the mothers in ICF with respect to reasonable meal management for 'optimal nutrition of family'. In addition, the government should try to make the various welfare policies to improve nutritional status of low income famines including the poor industrial complex-families.

한국 골프장의 친환경적 개발에 관한 연구 (Study of Pro-environmental Development for Golf Course in Korea)

  • 김광두
    • 아시안잔디학회지
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    • 제12권1호
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    • pp.49-78
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    • 1998
  • Nowadays, there are increasing demands of golf courses and it is necessary to make more golf courses than the present. To do this, we need to improve the environmental problems with the regional inhabitants, and it is said that the first thing to be considered in developing any golf course in Korea is to preserve the environment. In this context, the purpose of this study is to set forth several design factors to lessen the negative impacts which are accompanied with the development of golf courses. 1. The present conditions of golf courses in Korea Many new golf courses have come into being, particularly since the late 1980s, and now, in the year of 1997, over one hundred of golf courses are doing their business, yet the number of golf course is still less than required. So far, over a half of them have been made in the vicinity of Seoul on account of various reasons, and this has adversely affected on our natural environment. This unreasonable development of golf courses has caused serious water pollution, landslides and the other problems. Also, the topography of Korea is not good for golf courses. Although the demands of golf courses are increasing, the suitable sites for them are very limited, and therefore it is sometimes unavoidable to make golf courses on steep hills. Consequently, in designing golf courses in Korea, the most important thing is the balance between natural environment and artificial environment. 2.Eco-friendly golf course design factors 1) The concept of eco-friendly golf courses Ecologically sustainable and sound golf courses which are made by eco-friendly approaches 2)Basic conditions of eco-friendly golf courses (1)The most suitable sites (2) Conservation of existing ground as much as possible (3)Proper use of agricultural chemicals which have great impacts on the environment (4) Reasonable use of fertilizers (5) Developing a specialized fertilizer only for grass (6) Adaptation of organic agriculture (7) Improvement of grass sorts (8) Establishing reservoirs for purifying the water from golf courses 3) Eco-friendly golf courses (1) Location-Enough area /Gentle slope/Winding ground/Including lakes or streams /Not crossing wind's main direction Facing south or southeast /Suitable soIl for grass /Good drainage /Low level of underground water (2)Course layout and design -Consideration about existing contours as much as possible -Adaptation of Scotish design trend -Various holes' configuration -Consideration toward surrounding landscapes -Reducing grass areas -Giving buffer zones -Adapting computer methods in the process of site analysis and design (3) Eco-friendly considerations in constructing and managing golf courses -Protection of wildlife -Reuse of existing forests and preservation of topsoil -Renovation of old-fashioned courses -Reducing grass areas -Purification of water -Standization of management -Strict regulations against chemicals -Recycling organic materials -Through separation of the water inside golf courses and out of bounds -Getting proper construction works done in a due time 4.Eco-friendly considerations from a viewpoint of cultural environment 1) Well-matched landscape design and events planning 2) Implement of identifications and awarding systerns 3)Acknowledgement of superintendents' qualitications in the maintenance of golf courses 4)Increasing public golf courses and keeping good relationships with the neighbors near golf courses Key words: Pro-environmental development, Golf course.

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Determining Correlation between Experiences of a Sensory Courtyard and DAS (Depression, Anxiety and Stress)

  • Nam, Jinvo;Kim, Keunho
    • 인간식물환경학회지
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    • 제24권4호
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    • pp.403-413
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    • 2021
  • Background and objective: There is growing concern about the effects of modern society on mental health, coming with Covid-19-related caveats on depression, anxiety, and stress (DAS). This can be a subject to provide alternative methods which alleviate DAS. In line with this context, sensory gardens are widely acknowledged to stimulate the five major senses (sight, sound, taste, touch, and smell) and can have a significant (positive) impact on mental health. However, there is limited empirical evidence on the effect of these gardens with regard to alleviating DAS - particularly with respect to urban society This is a gab in knowledge how such limits can be addressed. Accordingly, this present study is clearly needed in order to verify if there are any correlations between sensory gardens and (positive) effects on DAS. The aim of this study was therefore to understand current levels of DAS in a high density building with a sensory garden in a courtyard and determine correlations between experiences in the sensory courtyard and levels of DAS. Methods: The Depression Anxiety and Stress Scale (DASS-21) was employed to test the level of DAS. Results: Additionally, 13 different factors associated with experiences in the building, including the stimulation of the five major senses in the sensory courtyard, were measured to reveal their contribution to mitigating depression, anxiety, and stress. It is noted that the average levels of DAS were 7.91, 7.77 and 9.01 respectively indicating that the mental health of participants requires mental health management. However, results show that factors associated with the sensory courtyard could improve mental health. For example, new social relationships, walking with colleagues, and the stimulation of each of the five major senses in the sensory garden could improve DAS. Conclusion: This illustrates that external experiences are more effective at mitigating depression, anxiety, and stress than internal ones. Factor analysis revealed four components: stimulating the five senses; internal and external facilities; internet-based device use; and new social relationships. There was a strong positive correlation between new social relationships and walking with colleagues. There were also strong positive correlations among the stimulation of each of the five senses. In conclusion, there are strong indications that sensory courtyards can help alleviate DAS and should therefore be promoted, particularly in the current Covid-19 situation wherein the physical and mental health of the public at large are threatened. Accordingly, courtyard design should be rethought in light of the relationship between the positive impact of sensory gardens and mental health.

모자건강관리를 위한 위험요인별 감별평점분류기준 개발에 관한 연구 (A Study on the Risk Factors for Maternal and Child Health Care Program with Emphasis on Developing the Risk Score System)

  • 이광옥
    • 대한간호학회지
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    • 제13권1호
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    • pp.7-21
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    • 1983
  • For the flexible and rational distribution of limited existing health resources based on measurements of individual risk, the socalled Risk Approach is being proposed by the World Health Organization as a managerial tool in maternal and child health care program. This approach, in principle, puts us under the necessity of developing a technique by which we will be able to measure the degree of risk or to discriminate the future outcomes of pregnancy on the basis of prior information obtainable at prenatal care delivery settings. Numerous recent studies have focussed on the identification of relevant risk factors as the Prior infer mation and on defining the adverse outcomes of pregnancy to be dicriminated, and also have tried on how to develope scoring system of risk factors for the quantitative assessment of the factors as the determinant of pregnancy outcomes. Once the scoring system is established the technique of classifying the patients into with normal and with adverse outcomes will be easily de veloped. The scoring system should be developed to meet the following four basic requirements. 1) Easy to construct 2) Easy to use 3) To be theoretically sound 4) To be valid In searching for a feasible methodology which will meet these requirements, the author has attempted to apply the“Likelihood Method”, one of the well known principles in statistical analysis, to develop such scoring system according to the process as follows. Step 1. Classify the patients into four groups: Group $A_1$: With adverse outcomes on fetal (neonatal) side only. Group $A_2$: With adverse outcomes on maternal side only. Group $A_3$: With adverse outcome on both maternal and fetal (neonatal) sides. Group B: With normal outcomes. Step 2. Construct the marginal tabulation on the distribution of risk factors for each group. Step 3. For the calculation of risk score, take logarithmic transformation of relative proport-ions of the distribution and round them off to integers. Step 4. Test the validity of the score chart. h total of 2, 282 maternity records registered during the period of January 1, 1982-December 31, 1982 at Ewha Womans University Hospital were used for this study and the“Questionnaire for Maternity Record for Prenatal and Intrapartum High Risk Screening”developed by the Korean Institute for Population and Health was used to rearrange the information on the records into an easy analytic form. The findings of the study are summarized as follows. 1) The risk score chart constructed on the basis of“Likelihood Method”ispresented in Table 4 in the main text. 2) From the analysis of the risk score chart it was observed that a total of 24 risk factors could be identified as having significant predicting power for the discrimination of pregnancy outcomes into four groups as defined above. They are: (1) age (2) marital status (3) age at first pregnancy (4) medical insurance (5) number of pregnancies (6) history of Cesarean sections (7). number of living child (8) history of premature infants (9) history of over weighted new born (10) history of congenital anomalies (11) history of multiple pregnancies (12) history of abnormal presentation (13) history of obstetric abnormalities (14) past illness (15) hemoglobin level (16) blood pressure (17) heart status (18) general appearance (19) edema status (20) result of abdominal examination (21) cervix status (22) pelvis status (23) chief complaints (24) Reasons for examination 3) The validity of the score chart turned out to be as follows: a) Sensitivity: Group $A_1$: 0.75 Group $A_2$: 0.78 Group $A_3$: 0.92 All combined : 0.85 b) Specificity : 0.68 4) The diagnosabilities of the“score chart”for a set of hypothetical prevalence of adverse outcomes were calculated as follows (the sensitivity“for all combined”was used). Hypothetidal Prevalence : 5% 10% 20% 30% 40% 50% 60% Diagnosability : 12% 23% 40% 53% 64% 75% 80%.

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불가(佛家) 목우도(牧牛圖)와 유·도(儒·道) 십마도(十馬圖) 비교 연구 - 유불도(儒佛道) 삼가(三家)의 심법(心法)을 중심으로 - (A Comparative Study on Buddhist Painting, MokWooDo (牧牛圖: PA Comparative Study on Buddhist Painting, MokWooDo (牧牛圖: Painting of Bull Keeping) and Confucian/Taoist Painting, SipMaDo (十馬圖: Painting of Ten Horses) - Focused on SimBeop (心法: Mind Control Rule) of the Three Schools: Confucianism, Buddhism and Taoism -nd Control Rule) of the Three Schools: Confucianism, Buddhism and Taoism -)

  • 박소현;이정한
    • 한국전통조경학회지
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    • 제40권4호
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    • pp.67-80
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    • 2022
  • 불가의 십우도(十牛圖)는 현재 우리나라 사찰 금당 벽화에서도 자주 보이는 일종의 선종화이다. 송대 이후 발달한 목우도는 마음을 비유한 소와 이를 다스리는 목동을 소재로 하여, 이후 다양한 계층의 사람들이 도화, 게송, 화운시 등 다양한 작품을 남겼다. 이는 비단 한 시대 중국 불가 사상에서만 국한된 현상이 아닌 시대와 사상, 국경을 초월한 범문화적으로 나타난 현상으로 그 영향을 살펴볼 수 있다. 본 연구는 기존 목우도 연구에서 미비했던 유불도 삼가 사상 문화적 측면에서 통섭하고자, 유불도 삼가 사상을 대표할 수 있는 목우도송을 선정하여 각 문헌의 저술 목적, 마음의 수행 방법, 구경지취(究竟旨趣)를 비교하였다. 구체적인 연구 결과는 다음과 같다. 첫째, 불가의 십우도(十牛圖)는 보명의 『목우도』와 곽암의 『심우도』로 대별 된다. 불가의 선종은 깨달음을 통한 해탈을 지향한다. 이에 불가의 『목우도』와 『심우도』는 모두 점수(漸修)의 수행방법으로 수심증도(修心證道)를 위하여 작성되었다. 하지만 이는 선종과 교학의 관점 차이에 따른 강조점이 달라 화제(畫題)와 게송이 달리 나타난다. 둘째, 보명의 『목우도』는 방할기용(棒喝機用)이란 방법을 통해 미목(未牧)에서 쌍민(雙泯)의 진공묘유(眞空妙有)에 이르기까지 수행 과정을 소개하였으며, 그 이면에는 쌍민의 일원상(一圓相)마저도 초월하는 것을 구경처(究竟處)로 삼고 있다. 셋째, 곽암의 『심우도』는 심우(尋牛)에서 입전수수(入鄽垂手)에 이르는 점수(漸修)의 수행 과정을 나타내고 있다. 이는 사교입선(捨敎入禪)을 통해 상구보리(上求菩提), 하화중생(下化衆生)하는 경지에 나아가 중생(衆生)과 함께하는 화광동진(和光同塵)을 구경처(究竟處)로 삼아 모든 중생의 불성(佛性)을 제도하고자 하였다. 넷째, 시미즈 슌류(清水春流)의 『유가십마도(儒家十馬圖)』는 보명의 『목우도』를 차용하여, 유가의 심학의 지취를 설파하는 '원불입유(援佛入儒)'의 특징이 있다. 이는 유가의 학문의 목적인 '학성현, 복기성[學聖賢, 復其性]'을 근거로 '제외안내(制外安內)'의 함양(涵養) 공부를 통해 도(道)와 합일된 군자, 즉 성인(聖人)을 지향한다. 그 구경처(究竟處)는 『중용』의 "상천지재, 무성무취(上天之載, 無聲無臭)"와 합치된다. 다섯째, 원명노인(圓明老人)의 『상승수진삼요(上乘修真三要)』는 보명의 『목우도』를 차용함과 동시에 자신의 지취를 설하기 위해 총 13장의 그림으로 구성되어 '원불입도(援佛入道)'의 특징이 있다. 도교는 양생술을 통한 장생불사의 신선 성취를 목적으로 한다. 이에 반환심성(返還心性)을 통해 심신(心身)을 모두 버리고 태극의 정기로 새롭게 잉태된 성태(聖胎)로 화하여 궁극적으로 '원래 시초인 자금선(紫金仙)을 지향한다는 점이 도교만의 독특한 특징으로 나타난다. 이의 구경처(究竟處)는 지도회홍(至道恢弘)의 도의 속성과 합치되는 법신청정(法身淸淨)이다.