• 제목/요약/키워드: Minimum important difference

검색결과 148건 처리시간 0.027초

군집화 기반 정상상태 식별을 활용한 시스템 에어컨의 냉매 충전량 분류 모델 개발 (Development of Classification Model on SAC Refrigerant Charge Level Using Clustering-based Steady-state Identification)

  • 김재희;노유정;정종환;최봉수;장석훈
    • 한국전산구조공학회논문집
    • /
    • 제35권6호
    • /
    • pp.357-365
    • /
    • 2022
  • 냉매 오충전은 에어컨에서 빈번하게 발생하는 고장 모드 중 하나로, 적정 충전량 대비 부족 및 과충전 모두 냉방 성능의 저하를 유발하므로 충전된 냉매량을 정확하게 판단하는 것이 중요하다. 본 연구에서는 퍼지 군집화 기법을 통한 정상상태 식별을 통해 냉매 오충전량을 다중 분류하는 모델을 개발하였다. 정상상태 식별을 위해 에어컨 운전 데이터에 대해 이동 평균 간의 차이를 활용한 퍼지 군집화 알고리즘을 적용하였으며, IFDR를 통해 기존 연구된 정상상태 판단 기법들과 식별 결과를 비교하였다. 이후, 시스템 내 상관성을 고려한 mRMR을 이용해 특징을 선택하였으며, 도출된 특징을 이용해 SVM 기반의 다중 분류 모델이 생성되었다. 제안된 방법은 시험 데이터를 통해 만족할 만한 분류 정확도와 강건성을 도출하였다.

도시 녹지와 그 주변 기온의 공간적 분포- 서울시 종로구 창경궁, 창덕궁, 종묘 주변을 사례로- (Spatial Distribution of Temperature in and around Urban Parks- A Case Study of around Changkyeong Palace, Changdeok Palace and Jongmyo in Seoul-)

  • 권영아;이현영
    • 대한지리학회지
    • /
    • 제36권2호
    • /
    • pp.126-140
    • /
    • 2001
  • 서울시 종로구에 위치한 창경궁, 창덕궁, 종묘와 그 주변 지역을 사례로 소규모의 도시 녹지(녹지율 100%)가 주변 시가지의 기온에 미치는 영향을 분석하였다. 연구에 이용된 자료는 2000년 9월부터 11월까지 실측한 최고.최저 기온값 및 차량이동관측에 의한 실시간 기온값, 서울시 자동기상관측소의 시간별 기온값, 서울시 토지 이용현황도 서울시 현존식 생도, 09시 지상일기도이다. 맑고 바람이 약한 날의 주간에는 토지이용상태가 기온의 공간적 분포에 영향을 미친다. 최고기온의 경우, 녹지로 구성된 고궁에서 기온이 가장 낮고 녹지에서 멀어져 시가지 쪽으로 갈수록 높아져 녹지와 시가지간의 기온차이는 최대 7.3$^{\circ}C$에 달한다. 또한 시가지 내에서도 토지이용상태가 주거지나 공급용지(병원이나 학교)인 곳보다 고밀도의 상업지역에서 기온이 더 높다 야간에는 냉기류의 흐름으로 토지이용상태뿐만 아니라 지형도 기온분포에 중요한 역할을 한다. 차량이동관측에 의한 녹지 주변 기온의 수평 단면도는 토지이용상태와 밀접한 관련성을 갖는데 녹지에서 멀어질수록 기온이 높아져 고궁 가장장리로부터 200m 떨어진 곳에서는 1$^{\circ}C$정도, 400m에서는 3~4$^{\circ}C$차이가 난다.

  • PDF

군용 열영상장비 최소분해가능온도차의 정량적 측정 방법 및 탐지거리 예측에 관한 연구 (A Study on the quantitative measurement methods of MRTD and prediction of detection distance for Infrared surveillance equipments in military)

  • 정영탁;임재성;이지혁
    • 한국산학기술학회논문지
    • /
    • 제18권5호
    • /
    • pp.557-564
    • /
    • 2017
  • 대한민국 군의 K 계열 전차에 장착되어 있는 열영상장비의 목적은 시계가 제한된 환경에서 외부의 적외선 영역의 정보를 인간이 인지할 수 있는 시각 정보로 변환하는 것이다. 열영상장비의 시계, 배율, 분해능, 변조전달함수, 잡음등가온도차, 최소분해가능온도차 등의 지표 중에서 최소 분해 가능 온도차(MRTD)는 공간주파수와 온도분해능을 복합적으로 표현할 수 있기 때문에, 열영상장비의 성능 표현에 있어 가장 중요한 파라메터이다. 그러나 NATO의 MRTD 표준 측정 방법은 많은 주관적인 요소를 포함하고 있다. 즉, 측정자의 정신 상태, 시력 등의 차이와 측정환경에 따라 측정 결과의 오차가 발생하므로 MRTD의 측정결과는 안정적이지 못하다. 따라서 본 논문에서는 정성적인 MRTD 측정 방법을 gary scale을 바탕으로 이미지 연산을 통한 정량적인 지표로 변환하였다. 흑상과 백상의 Gray scale 차이의 평균을 최소분해가능온도로 변환하여, 국방규격서에서 요구하는 성능요구조건의 충족여부를 판단할 수 있다. 또한 gray scale은 MRTD의 탐지/인지/식별의 판별기준으로 활용할 수 있다. 전차에 열영상장비가 탑재되어 작전을 수행할 때의 탐지 가능 거리를 안개, 폭우, 맑은 날씨 등의 다양한 환경조건에 따라 분석하였다.

노인의 가족지지와 삶의 질 (A Study on Perceived Family Support and the Quality of Life in the Elderly)

  • 신동순;홍춘실
    • 가정간호학회지
    • /
    • 제4권
    • /
    • pp.76-85
    • /
    • 1997
  • In modern society, the human average life span has been prolonged due to medical benefits and changes in society, which results in the rapid and world -wide increase in the population of elderly. Consequently, the field of nursing science, as well as the field of many other discipline, has shown increasing interests in issues on the elderly. In addition, to improve the quality of life for elderiy people a great deal of effort has been made. The purpose of our study is to analyze the correlation between family support and quality of life in order to develop basic data for nursing interventions to maintain life satisfaction of the elderly. The sample consists of 108 subjects residing at home whose ages are over 65 years old. The data has been collected, from November 11, 1996 to November 23, 1996, through interviewing the elderly using a questionnarie. For the family supoort we used two: 1) the 5 - point Likert scale questionnarie developed by Gallo and Warren (Family support I) and 2) the 5-point Likert scale developed by H. S. Kang(Family support II), and for the quality of life we used the 3 - point likert scale questionnarie developed by Choi, Young Hee. For data analysis we used percentages, means, Pearson Correlation Coefficient and ANOVA. The results of our study are as follows: 1. For perceived family support I & II, the minimum score is 12 & 19, the maximum score is 32 & 46, the mean score is 24.49 & 34.90, respectively. 2. For Quality of life, the minimum score is 13, the maximum score is 39, the mean score is 28.61. 3. there is a very strong correlation between the perceived family support of the subjects and Quality of life (for I r=0.35047, p<.001 and for II r= 0.60558, p<.001). 4. The relationship between the general characteristics of the elderly and our two variables. family support and Quality of life, is as follows: 1) According to age(for II F=5.32, p<.01), the amount of monthly pocket money(for II F= 3.52, p<.05), inmate(for I F=2.93, p<.05, for II F=2.84, p<.05), economics(for I F=8.99, p<.01. for II F=7.51. p<.01), supporter(for I F=4.01. p<.01. for II F=3.43, p<.01), there is a statistically significant difference in family support. 2) According to the amount of monthly pocket money(F=6.69, p<.01), inmate(F=2.24, p<.05), economics(F=15.38, p<.01), there is a statistically significant difference in Quality of life. In conclusion, it can be said that the family support is an important variable to the Quality of the elderly life.

  • PDF

일본 정지궤도 기상위성 Himawari-8을 이용한 에어로졸 광학정보 산출 및 검증 (Retrieval and Validation of Aerosol Optical Properties Using Japanese Next Generation Meteorological Satellite, Himawari-8)

  • 임현광;최명제;김미진;김준
    • 대한원격탐사학회지
    • /
    • 제32권6호
    • /
    • pp.681-691
    • /
    • 2016
  • 자외선, 가시광, 적외선 파장대역의 채널을 갖는 위성 관측에 기반한 다양한 에어로졸 정보산출 알고리즘에 대해 많은 연구가 이루어져 왔다. 본 연구에서는 최근 발사된 일본 기상위성 히마와리 8의 가시광-적외선 채널정보를 이용하여, 어두운 지표 위에서 에어로졸 광학정보를 산출하였다. 가시영역을 이용한 에어로졸 광학정보 산출은 지표신호의 정확한 제거가 매우 중요한데, 이는 최소반사도법을 사용하여 산출하였다. 본 알고리즘은 어두운 지표에서 에어로졸 광학정보를 산출을 하기에 구름, 사막 등과 같은 밝은 지표 위에서는 산출하지 않는다. AHI는 가시광채널 외에도, 다양한 적외 채널을 갖고 있어 공간 비균질성, 밝기온도차이(Brightness Temperature Difference, BTD) 등을 이용하여 구름제거가 가능하다. 밝기온도(Brightness Temperature, BT)를 이용해 하층운, 상층운 제거에 유리한 채널을 사용하여 구름을 제거하게 된다. Aerosol Optical Depth (AOD) 산출 결과로는 상관계수가 0.7, 기대오차(Expected Error, EE) 안에 있는 비율이 49%를 나타내고 있으며, 낮은 AOD에서도 정확한 산출이 이뤄지고 있음을 보이고 있다. 다만 베이징 허베이 지역에서는 에어로졸 광학두께를 과소모의하는 경향이 있는데, 이는 최소반사도법을 이용한 지표정보 산출이 실제 지표반사도보다 높게 지표면 정보를 추정하게 되기 때문으로 추정된다.

온도기반의 Beta Distribution Model 을 이용한 후지 사과의 성숙기 예측 (Predicting Harvest Maturity of the 'Fuji' Apple using a Beta Distribution Phenology Model based on Temperature)

  • 최인태;심교문;김용석;정명표
    • 한국환경과학회지
    • /
    • 제26권11호
    • /
    • pp.1247-1253
    • /
    • 2017
  • The Fuji variety of apple, introduced in Japan, has excellent storage quality and good taste, such that it is the most commonly cultivated apple variety in Gunwi County, North Gyeongsang Province, Korean Peninsula. Accurate prediction of harvest maturity allows farmers to more efficiently manage their farm in important aspects such as working time, fruit storage, market shipment, and labor distribution. Temperature is one of the most important factors that determine plant growth, development, and yield. This paper reports on the beta distribution (function) model that can be used to simulate the the phenological response of plants to temperature. The beta function, commonly used as a skewed probability density in statistics, was introduced to estimate apple harvest maturity as a function of temperature in this study. The model parameters were daily maximum temperature, daily optimum temperature, and maximum growth rate. They were estimated from the input data of daily maximum and minimum temperature and apple harvest maturity. The difference in observed and predicted maturity day from 2009 to 2012, with optimal parameters, was from two days earlier to one day later.

실내모형시험을 통한 연직배수재의 통수능력 및 스미어존 영향 평가 (A Assessment of Discharge Capacity of Vertical Drains and Smear Zone Effect from Model Test)

  • 천병식;김의석;도종남;국길근
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2008년도 추계 학술발표회
    • /
    • pp.1136-1143
    • /
    • 2008
  • The Vertical Drains(Sand Drains, Pack Drain, PBD) is used for Vertical Drains Method in domestic. Each of the drains is selected after it consider a field condition and efficiency of drain. A discharge capacity is very important factor, which to estimate a efficiency. And the smear Zone where disturbance area of in-suit by installation of Vertical Drains is important factor to select a drains. In this study, the complex discharge capacity test was operated for discharge capacity comparison of the Wing Drain and PBD. And a model test was operated to apprehend smear zone of the Wing Drain and PBD. From these tests, it was apprehended an engineering characteristic of vertical drain. The results of the complex discharge capacity test, a discharge capacity fell below $20cm^3/sec$ to $1cm^3/sec$ in more than overburden load $2.5kg/cm^2$. The Wing Drain maintained a over $40cm^3/sec$ in more than overburden load $2.5kg/cm^2$ and minimum discharge capacity $8cm^3/sec$. The results of the smear zone test, a influence bounds of smear zone was more larger in case of the Wing Drain(rectangle) than the PBD. But when a discharge capacity of Wing Drain is considered, it was concluded which smear zone bounds difference was effected in comparison with PBD. I think that it minimized a mandrel section to minimize a smear zone effect range

  • PDF

Evaluations and Comparisons of Body Surface Doses during Breast Cancer Treatment by Tomotherapy and LINAC Radiotherapy Devices

  • Lee, Hyun-Jik;Bae, Sun-Hyun;Cho, Kwang Hwan;Jeong, Jae-Hong;Kwon, Su-Il;Lee, Kil-Dong
    • 한국의학물리학회지:의학물리
    • /
    • 제28권4호
    • /
    • pp.218-225
    • /
    • 2017
  • Effects on skin caused by the dose from linear accelerator (LINAC) opposing portal irradiation and TomoDirect 3-D modeling treatment according to the radiation devices and treatment methods were measured, and a comparative analysis was performed. Two groups of 10 patients each were created and measurements were carried out using an optically stimulated luminescence dosimeter. These patients were already receiving radiation treatment in the hospital. Using the SPSS statistical program, the minimum and maximum average standard deviations of the measured skin dose data were obtained. Two types of treatment method were selected as independent variables; the measured points and total average were the dependent variables. An independent sample T-test was used, and it was checked whether there was a significance probability between the two groups. The average of the measured results for the LINAC opposing portal radiation was 117.7 cGy and PDD 65.39% for the inner breast, 144.7 cGy and PDD 80.39% for the outer breast, 143.2 cGy and PDD 79.56% for the upper breast, 151.4 cGy and PDD 84.11% for the lower breast, 149.6 cGy and PDD 83.11% for the axilla, and 141.32 cGy and PDD 78.51% for the total average. In contrast, for TomoDirect 3-D conformal radiotherapy, the corresponding measurement values were 137.6 cGy and PDD 76.44%, 152.3 cGy and PDD 84.61%, 148.6 cGy and PDD 82.56%, 159.7 cGy and PDD 88.72%, and 148.6 cGy PDD 82.56%, respectively, and the total average was 149.36 cGy and PDD 82.98%. To determine if the difference between the total averages was statistically significant, the independent sample T-test of the SPSS statistical program was used, which indicated that the P-value was P=0.024, which was 0.05 lower than the significance level. Thus, it can be understood that the null hypothesis can be dismissed, and that there was a difference in the averages. In conclusion, even though the treatment dose was similar, there could be a difference in the dose entering the body surface from the radiation treatment plan; however, depending on the properties of the treatment devices, there is a difference in the dose affecting the body surface. Thus, the absorbed dose entering the body surface can be high. During breast cancer radiotherapy, radiation dermatitis occurs in almost all patients. Most patients have a difficult time while undergoing treatment, and therefore, when choosing a radiotherapy treatment method, minimizing radiation dermatitis is an important consideration.

디지털 지상파 라디오 방송의 전송방식 결정요인에 관한 지상파 방송사의 인식차이와 쟁점 요인에 관한 연구 (A Study on the Cognitive Differences and Issue Factors of Terrestrial Broadcasters on Transmission System Determinants of Digital Radio Broadcasting)

  • 채수현;이영주
    • 방송공학회논문지
    • /
    • 제20권1호
    • /
    • pp.122-139
    • /
    • 2015
  • 지상파 TV의 디지털 전환이 완료되었지만 지상파 라디오는 전송방식을 결정하지 못해 아날로그 방송을 유지하며 표류하고 있는 상태이다. 본 연구에서는 지상파 방송사의 종사자를 대상으로 상호지향성 모델을 토대로 디지털 라디오 전송방식을 결정하는 중요 요인에 대한 인식차이를 살펴보고 쟁점 요인을 도출하였다. 연구결과, 지상파 방송 3사는 디지털 라디오가 점유할 주파수 대역 선택에서 가장 큰 인식의 차이가 있으며 제작과 송출의 병행 여부, 주파수 이용 효율성, 방송 품질과 서비스 정도는 서로 의견의 차이가 없는 것으로 나타났다. 그리고 디지털 라디오 방송의 전환에 있어 가장 큰 쟁점 요인은 FM 라디오방송이 사용하는 주파수대역(88-108 MHz)과 지상파 DMB방송 주파수대역(VHF Ch7~13), FM 라디오방송 인접대역(76~88MHz: VHF Ch5~6) 중 어떤 주파수 대역을 디지털 라디오용으로 선택하는지의 문제, 즉 DAB+, HD-Radio, DRM+ 가운데 특정 전송방식을 선택하는 문제로 귀결되었다. 이에 본 연구에서는 제작 송출 병행이 가능하고 송 중계소 1-2개로 송신 효율을 높일 수 있고 신규 사업자 진입이 가능한 방식을 채택함으로써 라디오방송서비스의 품질과 이용자의 만족도를 높일 것을 제안하고자 한다.

완충녹지 활용의 적정성 평가 -대전시 서구 완충녹지를 대상으로 (A Study on the Appropriateness Evaluation of Utilization of green buffer zone - Focusing on green buffer zone, Daejeon City Seo-gu)

  • 김선민;이시영
    • 토지주택연구
    • /
    • 제10권4호
    • /
    • pp.41-50
    • /
    • 2019
  • This study was started to study the buffer zone of Daejeon metropolitan city in order to study the policy and environment for the suitability evaluation of the use of green buffer zone. The target of the study was selected as the buffer zone of western buffer, which is frequently used in the Daejeon Metropolitan City, and a preliminary index was selected to evaluate the suitability of the green buffer zone. AHP analysis was conducted to increase the reliability of the preliminary indicators and the weight was analyzed by questionnaires to experts and practitioners. In addition, based on the existing statistical data, we rebuilt the green buffer zone and investigated the current condition, and compared and analyzed the green buffer zone and the places where they did not. The results are as follow. First, unlike the statute interpretation that construction can not be done in buffered green spaces, green buffer zones have been utilized in various ways. However, the lack of advanced citizen consciousness of the residents, the responsibility of the responsible person, and the problem of the management office alone are causing problems. Second, according to the results of AHP questionnaire analysis, functional and stability among the appropriateness indexes of green buffer zone utilization were evaluated highly. Park accessibility and utilization potential also weighed somewhat, and it was judged that the epochal trend was more important in the use of green buffer zones. Third, analysis of the status of Western green buffer zones in Daejeon showed that the utilization rate was more than half. This suggests the necessity of judging the appropriateness of the application of the green buffer zone effectively due to the change of the perception of the green buffer zone of the residents. Fourth, as a result of comparing and analyzing the site where the site is used and the site where it is not, it is found that it is used within a range that does not greatly affect each index. However, as the stability has decreased, we have decided that the utilization method is most damaging to the green zone, and we should strive to improve the stability in future. Finally, the analysis of a red clay road and a red clay road sites decreased from Class I of stability to Grade II. However, the fall figure showed a difference between the 13 % drop rate of the target location and the 5% decline rate of utilization. The difference was analyzed as the difference of width of a red clay road. This can be regarded as one of the ways of damaging the green zone to the minimum extent, which is a great advantage in selecting the future utilization plan.