평면도형의 둘레와 넓이, 입체도형의 겉넓이와 부피에 대한 초등학교 6학년 학생들의 수행 능력 조사

임영빈,임예은,김수미 한국수학교육학회 2019 수학교육 Vol.58 No.2

Among the measurement attributes included in the elementary school mathematics curriculum, perimeter, area, volume and surface area are intensively covered in fifth and sixth graders. However, not much is known about the level of student performance and difficulties in this area. The purpose of this study is to examine the understanding and performance of sixth-grade elementary school students on some ideas of measurement and ultimately to give some suggestions for teaching measurement and the development of mathematics textbooks. For this, diagnosis questions were developed in relation to the following parts: measurement of perimeter and area of plane figure, measurement of surface area and volume of solid figure, and the relationships between perimeter and area, and the relationships between surface area and volume. The performances of 95 sixth graders were analyzed for this study. The results showed children's low performance in the measurement area, especially measurement of perimeter and surface area, and relationship of the measurement concepts. Finally, we proposed the introduction order of the measurement concepts and what should be put more emphasis on teaching measurement. Specifically, it suggested that we consider placing a less demanding concept first, such as the area and volume, and dealing more heavily with burdensome tasks such as the perimeter and surface area. 초등학교 교육과정에 포함된 측정 속성 가운데 둘레와 넓이, 겉넓이와 부피는 5, 6학년에서 집중적으로 다루어진다. 그러나 이 영역에서 학생들의 수행능력이 어느 정도가 되며 어떤 문제가 있는지에 대해서는 알려진 바가 많지 않다. 이 연구는 평면도형의 둘레와 넓이, 입체도형의 겉넓이와 부피에 대한 초등학교 6학년 학생들의 이해 정도를 진단하고, 각 요소별 수행 능력을 비교 분석하여 차후 수학 교과서 개발 및 측정 영역 지도를 위한 시사점을 도출하고자 하였다. 이를 위해 둘레, 넓이, 겉넓이, 부피, 둘레와 넓이의 관계, 겉넓이와 부피의 관계에 관련된 문항을 구성하여 6학년 학생 95명을 대상으로 수행 능력을 분석하였다. 분석결과 초등학교 6학년들의 수행능력이 둘레, 겉넓이, 둘레와 넓이의 관계, 겉넓이와 부피의 관계 영역에서 특히 낮은 것으로 드러났다. 이러한 연구 결과를 바탕으로 둘레와 넓이, 겉넓이와 부피 개념의 도입 순서와 지도 방법, 지도 순서 등에 대한 몇 가지 아이디어를 제안하였다.

가상 유양동삭개술 모델에서 유양동 기체 생리의 변화

정대한,정훈,류은웅,박철언,변재용,여승근,박문서 대한이비인후과학회 2010 대한이비인후과학회지 두경부외과학 Vol.53 No.5

Background and ObjectivesZZIt is essential to understand gas physiology of mastoid cavity to study the pathophysiology of middle ear diseases, and the surface area and volume of mastoid mucosa are important parameters for evaluating gas physiology. However, the surface area and mastoid volume of the mastoid cavity have not been practically measured yet. Therefore, we measured and compared surface area and volume of the mastoid cavity before and after mastoidectomy using a virtual mastoidectomy model. Subjects and MethodZZWe performed a virtual mastoidectomy using 10 cases of temporal bone CT indicating pneumatic mastoid. First, we removed all air cells after outlining with irregular AOI function after loading axial CT images to Image-Pro Plus 4.0. Then we filled the removed area with equal planes using local equalization filter. Finally, we calculated and compared the total surface area, volume and area to volume (A/V) ratio by estimating their circumference and area. ResultsZZThe mean surface area of pneumatized mastoid cavity was 127.8 cm2 (range: 94.2-165.3 cm2), and the mean volume was 7.1 cm3 (range: 5.2-11.0 cm3). The mean surface area and volume were altered to 42.8 cm2 (range: 35.9-55.0 cm2) and 12.6 cm3 (range: 10.3-18.7cm3), respectively, after virtual mastoidectomy. As a result, the A/V ratio decreased from 18 to 3.4 after a virtual mastoidectomy in the pneumatic mastoid cavity. ConclusionZZWhen a complete mastoidectomy is performed in the pneumatic mastoid, the surface area is decreased by one third compared to a relatively minor increase in volume. Therefore,the surface area per unit volume is expected to greatly decrease after mastoidectomy. Some physiologic problems occurring after mastoidectomy could be more accurately explained using a virtual mastoidectomy model. Korean J Otorhinolaryngol-Head Neck Surg 2010;53:284-9

The impact of urban green areas on the surface thermal environment of a tropical city: a case study of Ibadan, Nigeria

Ifeoluwa A. Balogun,Mojolaoluwa T. Daramola 대한공간정보학회 2019 Spatial Information Research Vol.27 No.1

This study assesses the relative impact of green areas on the surface thermal characteristics of an urban area. From this study, the existence of the Park Cool Island (PCI) around the green areas and surrounding zones of the green area was noted, as surface temperatures were lower at the green areas and higher at the outer boundaries. Agodi gardens had the highest vegetation cover of 62.1% and was the area with the lowest mean surface temperature (26.79 C), while Agugu green area had the lowest vegetation cover of 20.7% and had the highest mean surface temperature (27.75 C). Green areas with higher vegetation cover percentages had higher rate of change of PCI with buffer distance compared to the other two green areas that had lower percentages of vegetation cover. The green areas were identified for their cooling roles on surface temperature within the urban centres of Ibadan as the surface temperature intensities were of the order of 1–2 C lower within the 500-m buffer zone. The findings, therefore, brings to light the need for increased greenery within the urban areas of the city, and also provide information for urban planners and designers on the need for green spaces in mitigating heat island phenomenon in the city.

경상남도 행정구역별 불투수면적률 현황 및 변화 연구

김현준,최윤희,김학관,장민원 한국농촌계획학회 2023 농촌계획 Vol.29 No.4

This study aimed to analyze the recent status and changes in impervious surface areas and their ratios across regions in Gyeongsangnam-do, providing fundamental data for regional development and impervious surface management. Based on the ‘Guidelines for Calculating Water Cycle Management Indicators for Nonpoint Pollution Source Control(Ministry of Environment)’, we processed the land characteristics survey map(shapefile) from 2018 and 2022 to analyze impervious surface area and their rates by administrative boundaries. The impervious surface area in Gyeongsangnam-do increased from 75,652 ha in 2018 to 81,055 ha in 2022, with the rate rising by 0.51% from 7.18% to 7.69%. The average of impervious surface area across 545 eupmyeon units expanded by approximately 9 ha, from 139.8 ha in 2018 to 148.8 ha in 2022, with the rate increasing by 0.71%. Concurrently, the whole population declined by 2.8% while the number of households surged by 6.4%, correlating with the growth in impervious areas. Despite population decreases, factors such as population migration, increased household fragmentation, new residential developments, and industrial facility expansions have consistently contributed to the rise in impervious surface area. Notably, even in areas with high impervious surface area rate, significant disparities existed between urbanized areas and predominantly rural regions. Furthermore, about 333 units(61% of the whole eupmyeons), showed negligible changes in their impervious surface area rate, with an increase of less than 0.5%.

도시열섬완화를 위한 토지 이용 유형별 합리적 녹지율 분석

송봉근 ( Bong Geun Song ),박경훈 ( Kyung Hun Park ) 한국지리정보학회 2015 한국지리정보학회지 Vol.18 No.2

본 연구는 다양한 토지이용유형별로 도시열섬현상을 완화하기 위한 합리적 녹지율을 분석하고자 하였다. 토지이용유형은 단독주택과 공동주택, 공공시설, 상업지역, 공업지역의 5가지 유형을 고려하였고, 녹지지역은 토지피복도에서 수목 속성을 추출하여 활용하였다. 열섬효과는 주간 및 야간에 촬영된 다중시기의 ASTER TIR 영상의 표면온도를 이용하였다. 주간시간은 야간시간보다 녹지의 표면온도 저감 효과가 큰 것으로 나타났다. 토지이용유형별로는 주간시간에 단독주택에서 녹지율에 따른 표면온도 저감효과가 가장 뚜렷했지만, 야간시간에는 토지이용유형별로 차이가 크지 않았다. 공업지역은 녹지의 표면온도 저감 효과가 낮았다. 토지이용유형별 도시열섬완화를 위한 합리적 녹지율을 산출한 결과, 주간시간은 단독주택과 공동주택, 상업지역에서 녹지율이 40~50% 사이일때, 표면온도가 가장 낮았고, 야간시간은 녹지율별로 표면온도 변화가 크지 않았다. 따라서 본 연구의 결과는 도시개발계획 단계에서 도시열섬완화를 위해 효과적인 녹지면적을 제시할 수 있을 것으로 판단된다. The purpose of this study is to analyze reasonable green area ratios for mitigating urban heat island considering various land use types. Land uses of 5 types such as single residential, multi residential, commercial area, public facility, and industrial area were considered. Green areas were extracted from the tree attribution of land cover. Effect of urban heat island was analysed by the surface temperature of ASTER thermal infrared radiance scanned daytime and nighttime. Mitigation effect of green area at daytime was higher than nighttime. Surface temperature of green area was low in single residential at daytime. But the difference of surface temperature by each land use type was small. The effect of surface temperature mitigation of green area was lower in industrial area. The results of reasonable green area ratios for mitigating urban heat island indicate that surface temperature was the lowest with green area ratio of 40~50% in single residential, multi residential, and commercial area at daytime. Surface temperature of nighttime was not changed much by green area ratios. Therefore, the results of this study will be suggested in urban development planning to construct effectively green area for mitigating urban heat island.

Surface-Based Parameters of Brain Imaging in Male Patients with Alcohol Use Disorder

임성진,이상구,이정환,김시경,신철진,손정우,주가원,이상익 대한신경정신의학회 2016 PSYCHIATRY INVESTIGATION Vol.13 No.5

ObjectiveaaThe structural alteration of brain shown in patients with alcohol use disorder (AUD) can originate from both alcohol effects and genetic or developmental processes. We compared surface-based parameters of patients with AUD with healthy controls to prove the applicability of surface-based morphometry with head size correction and to determine the areas that were sensitive to brain alteration related to AUD. MethodsaaTwenty-six abstinent male patients with AUD (alcohol group, mean abstinence=13.2 months) and twenty-eight age-matched healthy participants (control group) were recruited from an inpatient mental hospital and community. All participants underwent a 3T MRI scan. Surface-based parameters were determined by using FreeSurfer. ResultsaaEvery surface-based parameter of the alcohol group was lower than the corresponding control group parameter. There were large group differences in the whole brain, grey and white matter volume, and the differences were more prominent after head size correction. Significant group differences were shown in cortical thicknesses in entire brain regions, especially in parietal, temporal and frontal areas. There were no significant group differences in surface areas, but group difference trends in surface areas of the frontal and parietal cortices were shown after head size correction. ConclusionaaMost of the surface-based parameters in alcohol group were altered because of incomplete recovery from chronic alcohol exposure and possibly genetic or developmental factors underlying the risk of AUD. Surface-based morphometry with controlling for head size is useful in comparing the volumetric parameters and the surface area to a lesser extent in alcohol-related brain alteration.

高密度 Polyethylene의 極小部分 熱處理에 의한 表面形態變化

金東建,金圭範 진주산업대학교 2000 산업과학기술연구소보 Vol.- No.7

This study is carried out to investigate the surface morphology changes of the annealed high-density polyethylene film on micro-area with iron core at 130℃. The results obtained are as follows ; In consequence of the annealed polyethylene film on micro-area, each area -the area where iron core was contacted, the contact boundary, the area which is distant from the contact boundary, and the area which is more distant from the contact boundary- had a different surface morphology. On the basis of the SEM observations, the orientation of annealed polyethylene film on micro-area was found to become higher by 8 times stretching treatment. And, the surface and inside structure of this sample changed in the area where the iron core was contacted. The mechanical properties of the annealed polyethylene film on micro-area were depended upon the treatment area. The strength increased in the area where iron core was contacted. This fact was also support by the SEM result.

지표수-지하수 연계 기반의 통합수자원 관리를 위한 단위유역 제안

김규범,황찬익 한국수자원학회 2020 한국수자원학회논문집 Vol.53 No.S-1

In South Korea, 850 standard watersheds and 7,807 KRF catchment areas have been used as basic maps for water resources policy establishment, however it becomes necessary to set up new standard maps with a more appropriate scale for the integrated managements of surface water-groundwater as well as water quantity-quality in the era of integrated water management. Since groundwater has a slow flow velocity and also has 3-D flow properties compared to surface water, the sub-catchment size is more effective than the regional watershed for the evaluation of surface water-groundwater interaction. The KRF catchment area, which has averagely a smaller area than the standard watershed, is similar to the sub-catchment area that generally includes the first-order or second-order tributaries. Some KRF catchment areas, which are based on the surface reach, are too small or large in a wide plain or high mountain area. Therefore, it is necessary to revise the existing KRF area if being used as a unit area for integrated management of surface-water and groundwater. A unit watershed with a KRF area of about 5 to 15 km2 can be effective as a basic unit for water management of local government considering a tributary composition and the location of groundwater wells, and as well it can be used as a basic tool for water demand-supply evaluation, hydrological observation system establishment, judgment of groundwater permission through a total quantity management system, pollution assessment, and prioritizing water policy, and etc. 현재 우리나라는 수자원단위지도의 표준유역(850개) 및 KRF의 집수구역(7,807개) 등의 기준 도면이 수자원 정책 수립의 기본 도면으로 활용되고 있으나, 물관리 일원화 시점에 맞추어 지표수-지하수의 연계 관리 및 수량-수질 통합관리를 위해서는 보다 적절한 규모의 표준 도면 설정이 필요해 보인다. 지표수에 비하여 지하수는 느린 이동 속도를 보이고 3차원 흐름 특성을 갖고 있으므로 지표수-지하수 연계 평가를 위해서는 광역적 규모의 유역 보다는 준 유역 규모가 보다 효과적인데, 표준유역보다 평균 면적이 작은 KRF 집수구역은 1차 또는 2차 지류를 포함하는 준 유역 규모에 해당한다. 그러나, KRF는 지표수 수계를 기준으로 구역을 구분하였기 때문에 넓은 평지 또는 높은 산악지역에서는 지나치게 작거나 큰 면적을 갖고 있다. 따라서, 지표수-지하수 연계 통합 관리에 적합한 단위 유역은 기존 KRF 집수구역을 수정하여 설정하는 것이 필요하다. 이로부터 설정될 개소 당 약 5 ~ 15 km2 면적의 단위 유역은 지류의 구성과 관정의 위치를 고려할 때 지방자치단체의 수자원 관리의 기본 단위가 될 수 있으며, 물 수요-공급 평가, 수문 계측 시스템의 배치, 지하수 허가 총량 기준, 오염의 평가, 정책의 우선 순위 결정 등 실질적인 수자원 통합관리의 기본 수단으로 활용 가능할 것이다.

Ergonomic human errors in the estimation on the involved body surface area for psoriatic skin

( Guk Jin Jeong ),( Jae Min Kim ),( Ji Ho Park ),( Kapsok Li ),( Beom Joon Kim ),( Myeung Nam Kim ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.2

Background: Although psoriasis area and severity index (PASI) is the most widely accepted severity measure for psoriatic skin lesions, its limitations were repeatedly reported in the literature. Objectives: This study aimed to investigate the extent and nature of human errors in the estimation on the involved body surface area with PASI and to reveal their clinical implications. Methods: 43 images of skin lesions on the back of psoriatic patients were prepared. 36 MDs estimated the area involved in the image, and express it as a percentage of total area of back. We compared human evaluators’ answers with gold standard which was obtained by photometric method using image analysis software. Results: With respect to the area index of PASI (1 through 6), ratio of correct assignments by human evaluators were surprisingly low, only 49.4% in average. This error originated from two major factors. First is the inaccurate estimation of involved area. Error-prone images tended to have greater number of lesions and complicated outlines. Second is the human evaluators’ tendency of overestimation and thus their magnitude was approaching half the span of PASI area indices. Conclusion: In this study, we analyzed the human errors in the estimation of area (index) with PASI, and suggest what requirements the ideal system should have for practical application in clinics.

Landsat 8 위성자료를 이용한 도심녹지 냉각효과 분석

김근회,이영곤,김재환,최희욱,김백조 대한원격탐사학회 2018 大韓遠隔探査學會誌 Vol.34 No.2

Urban green areas or forest regions play an important role in lowering the air temperature of the surrounding areas. This cooling effect does not only affect inside of the green areas, but also extends into neighboring streets and buildings. In this study, the Land Surface Temperature (LST) are retrieved from the Landsat 8 satellite data for 8 clear days in Seoul, Korea from 2013 to 2015, and used for analyzing the cooling effect at an urban green region, Seonjeongneung, located in the southern part of Seoul. The LST distribution from the boundary of the Seonjeongneung presents that the cooling effect of the green areas was found to extend in many directions into the urban areas. The LST estimations of residential and commercial areas around the Seonjeongneung are also analyzed to assess how the green areas affect the type of land cover and the surroundings in the urban areas. Relatively lower LST for the residential areas from the Seonjeongneung boundary ranges from 100 to 250 m, resulting in an average cooling effect of 2.3°C. On the other hand, the LST distribution in the commercial areas shows that the effective distance of green areas are relatively low in the range of 0 to 200 m, which means the average cooling effect is approximately 0.3°C. This result shows that the cooling effect of the Seonjeongneung is clearly noticeable, particularly, the residential areas show greater cooling effect than commercial areas. 도심녹지는 도심 주변의 높은 기온을 낮춰 주는 중요한 역할을 한다. 도심녹지의 냉각효과는 녹지내부 뿐만 아니라 주변 도로와 빌딩 지역에도 영향을 준다. 도심녹지가 주변에 미치는 영향을 분석하기 위해2013년부터 2015년까지 관측된 Landsat 8 위성자료를 이용하여 서울 선정릉 주변의 지표면온도를 산출하였다. 선정릉 주변의 지표면온도 분포를 분석한 결과, 도심녹지의 냉각효과는 녹지를 중심으로 여러 방향에서 나타나는 것을 확인하였다. 도심녹지의 냉각효과에 미치는 토지피복의 영향을 살펴보기 위하여 주거지역과 상업지역에 대해 냉각효과를 분석한 결과 주거지역의 냉각효과 범위가 100∼250 m로 나타났고, 평균 2.3°C 의 냉각효과를 보였다. 반면, 상업지역의 냉각효과 범위는 0∼200 m 였고, 평균 약 0.3°C의 냉각효과를 보였다. 이러한 분석 결과를 통해 도심녹지의 냉각효과는 상업지역보다 주거지역에서 강도와 범위가 큼을 알수 있었다.