• 한국주거학회논문집
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• 제19권6호
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• pp.105-114
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• 2008

The purpose of this study is to classify playground types according to the physical characteristics of playgrounds in child care facilities, to analyze the needs of care-givers and to evaluate the adequacy of playgrounds according to playground types. The specific areas discussed in this study were the evaluation of the adequacy in the physical characteristics of playgrounds for children's outdoor play activities by the care-givers, who assist in the outdoor play activities of children and manage safety in the playground, and a report on playground requirements of them. Data was collected from field survey carried out to investigate the physical characteristics of playgrounds of 21 child care facilities. This survey incorporated a structured-questionnaire for the purpose of evaluating the adequacy of the physical characteristics of playgrounds (location and size of the playground, play equipments, the composition of play areas, ground covers, and location of sidewalk in the playground) by the 181 care-givers from the facilities and investigating the needs of them. The major results showed the following. 1) In field survey, it was observed that while the location and the size of the playgrounds varied widely, ground cover, play equipments, and the composition of play area turned out to be identical, regardless of the location and the size of the playgrounds. 2) The playgrounds were classified into five types according to the number of children and the size of the playground. The five types include A-type as a large-scale facility/smallsize playground, B-type as a small-scale facility/large-size playground, C-type as a small-scale facility/small-size playground, D-type as a middle-scale facility/large-size playground, and E-type as a large-scale facility/large-size playground. 3) The adequacy of the physical characteristics of playground in the D-type was evaluated to be higher than that of the other types. The adequacy of the C-type playground was evaluated to be lower than that of the other types in terms of size and the composition of play areas within the playground. 4) The care-givers of the D-type and the E-type playground expressed a desire to install various play equipments, while the care-givers of the C-type playground did not wish to install play equipment. 5) Various outdoor play areas were needed in the D-type playground.

• 한국표면공학회지
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• 제50권5호
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• pp.386-391
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• 2017

Two kinds of steels whose compositions were Fe-34.4Cr-14.5Ni-2.5Mo-0.4W-0.4Mn-0.5Si-(0.009 or 0.35)S (wt.%) were centrifugally cast, and oxidized at $900^{\circ}C$ for 50-350 h in order to find the effect of sulfur on the high-temperature oxidation of Fe-34.4Cr-14.5Ni-2.5Mo-0.4W-0.4Mn-0.5Si-(0.009 or 0.35)S (wt.%) alloys. These alloys formed oxide scales that consisted primarily of $Cr_2O_3$ as the major oxide and $Cr_2MnO_4$ as the minor one through preferential oxidation of Cr and Mn. They additionally formed $SiO_2$ particles around the scale/alloy interface as well as inside the matrices. The high affinity of Mn with S led to the formation of scattered MnS inclusions particularly in the 0.35S-containing cast alloy. Sulfur was harmful to the oxidation resistance, because it deteriorated the scale/alloy adherence so as to accerelate the adherence and compactness of the formed scales.

• 천문학회지
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• 제37권5호
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• pp.355-359
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• 2004

Differential Faraday Rotation measurements between the images of same background source, of multiply-imaged gravitational lens systems can be effectively used to provide a valuable probe to establish the existence of large-scale ordered magnetic fields in lensing galaxies as well as galaxy clusters. Estimates of the magnetic field in lens galaxies, based on the radio polarization measurements do not appear to show any clear evidence for evolution with redhsift of the coherent large scale magnetic field between redshift of 0.9 and the present epoch. However, our method clearly establishes the presence of coherent large scale magnetic field in giant ellitpical galaxies.

• International Journal of Concrete Structures and Materials
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• 제9권4호
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• pp.463-473
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• 2015

Three full-scale instrumented test slabs were constructed and tested using a heavy vehicle simulator (HVS) to evaluate the structural behavior of internally cured concrete (ICC) for use in pavements under Florida condition. Three mix designs selected from a previous laboratory testing program include the standard mixture with 0.40 water-cement ratio, the ICC with 0.32 water-cement ratio, and the ICC mixture with 0.40 water-cement ratio. Concrete samples were prepared and laboratory tests were performed to measure strength, elastic modulus, coefficient of thermal expansion and shrinkage properties. The environmental responses were measured using strain gages, thermocouples, and linear variable differential transformers instrumented in full-scale concrete slabs. A 3-D finite element model was developed and calibrated using strain data measured from the full-scale tests using the HVS. The results indicate that the ICC slabs were less susceptible to the change of environmental conditions and appear to have better potential performance based on the critical stress analysis.

• 대한기계학회논문집
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• 제9권6호
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• pp.732-742
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• 1985

본 논문에서는 이 2차원 재부착분류(본문에서는 stepped wall jet라 명명함) 유동장을 재부착상류 부분, 재부착점 근방, 재부착 이후의 재발전 벽면분류 지역의 세 영역으로 구분하여 재부착 길이, 평균속도, 벽면정압을 측정하고 on-line에 의한 디지 틀 데이터 처리기법을 이용하여 난류강도, 레이놀즈 전단응력, 속도의 3승적(triple velocity product), integral length scale, Taylor's microscale 등을 실험적으로 구 하여 재부착 상류 부분에서는 자유분류와 비교하고, 재부착 이후에서는 2차원 벽면분 류와 비교하기로 한다.그리하여 초기 교란을 받는 분류가 벽면에 재부착하여 2차원 벽면분류로 재발전되어 가는 과정에 있어서의 평균 유동장과 급격한 변화를 갖는 난류 특성을 상세히 조사하여, 보다 일반적으로 적용될 수 있는 난류모델을 개발함에 있어 서 실험적인 자료를 제공하고자 한다. Fig. 1은 본 실험의 유동장에 대한 개약도를 보여주고 있다.

• 성인간호학회지
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• 제21권4호
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• pp.423-434
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• 2009

Purpose: This study was conducted to evaluate successful aging (SA) in elderly individuals and to determine the factors that influence SA. Methods: The subjects included 207 elderly individuals from D city, Korea. The data were obtained between July 1 and August 30, 2008. The participants were assured of anonymity and confidentiality. For the evaluation, Kim & Shin's SA scale, Lawton's instrumental activities of daily living (IADL) scale, Jon's self-esteem scale, Kee's geriatric depression scale short form-Korean (GDSSF-K), and Hong's productive activities scale were used. The data were analyzed using descriptive statistics, the t-test, analysis of variance (ANOVA), and Pearson correlation coefficients; multiple regression analysis was performed using the SPSS/WIN 10.0 program. Results: The maximum score for SA was 34, and the mean score was 22.62. It was found that SA was significantly correlated to IADL, self-esteem, depression, and productive activity. Depression was the most powerful predictor of SA and it accounted for 40.6% of the total variance in SA. Self-esteem, productive activity, living situation, economic status, and age together accounted for 62.1% of the total variation in SA. Conclusion: Depression, self-esteem, and productive activity were identified as variables that influence SA. On the basis of these results, we conclude that nurses should assist elderly individuals in order to facilitate SA. Moreover, individualized nursing management strategies must be developed in order to facilitate SA.

• 한국초전도ㆍ저온공학회논문지
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• 제16권4호
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• pp.62-65
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• 2014

To minimize most heat loss of current lead for high-temperature superconducting (HTS) rotating machine, the choice of conductor properties and lead geometry - such as length, cross section, and cooling surface area - are one of the various significant factors must be selected. Therefore, an optimal lead for large scale of HTS rotating machine has presented before. Not let up with these trends, this paper continues to improve of diminishing heat loss for HTS part according to different model. It also determines the simplification conditions for an evaluation of the main flux flow loss and eddy current loss transient characteristics during charging and discharging period.

• Computers and Concrete
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• 제7권2호
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• pp.159-167
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• 2010

This paper demonstrates numerical techniques for complex large-scale modeling with microplane constitutive theories for reinforced high strength concrete, which for these applications, is defined to be around the 7000 psi (48 MPa) strength as frequently found in protective structural design. Applications involve highly impulsive loads, such as an explosive detonation or impact-penetration event. These capabilities were implemented into the authors' finite element code, ParaAble and the PRONTO 3D code from Sandia National Laboratories. All materials are explicitly modeled with eight-noded hexahedral elements. The concrete is modeled with a microplane constitutive theory, the reinforcing steel is modeled with the Johnson-Cook model, and the high explosive material is modeled with a JWL equation of state and a programmed burn model. Damage evolution, which can be used for erosion of elements and/or for post-analysis examination of damage, is extracted from the microplane predictions and computed by a modified Holmquist-Johnson-Cook approach that relates damage to levels of inelastic strain increment and pressure. Computation is performed with MPI on parallel processors. Several practical analyses demonstrate that large-scale analyses of this type can be reasonably run on large parallel computing systems.

• 한국조경학회지
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• 제15권1호
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• pp.39-67
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• 1987

삼림경관지의 물리적 환경이 지닌 시각적 질을 계량적 접근방법으로 분석하여 환경설계에 객관화된 기초자료를 제시하고자, 자연삼림경관의 경관가치를 Iveson 법에 의하여 평가하고, 삼림내 주리용공간에 대하여는 S.D Scale을 측정하고, 인자분석 Algorithm을 통하여 이미지 구호를 밝혔으며, 시각적 선호성 및 S.B.E Method에 의한 시각적 선호도를 파악한 결과는 다음과 같다. 1. Iverson 인자 I과 IV가 높은 치를 보이는 지점일수록 경관의 가치순위가 높게 나타났으며, 인공구조물이 공잔적으로 일관된 맥락을 유지하는 분배와 연종의 상관관계를 보이지 않고 이질적으로 작용하는 지점에서는 낮은 치를 보였다. 인공요소를 자연경관요소에 동질적으로 융합시켜 Iverson 인자 IV의 측정치를 높이는 설계기법이 중요하다 하겠다. 2. 각 조사지점 공히 계절에 따른 S.D. Scale 치의 차이가 나타났으며, 삼림경관지에서 인공구조물이 보완적, 융합적으로 작용하는 공간에서는 시각적 연속성 구조물의 형태적 간결성 강조성 이질요소의 통일성 및 동화성 등의 어의미분척도가 이미지의 주성분석 변수로 나타났다. 3. 삼림경관지의 공간 이미지를 함축하는 변인은 종합평가, 개성, 정연성, 역량성, 품격, 친근감 및 공간규모 등 7개의 인자군으로 분석되었으며, 인자수 제어방법에 의하여 T.V. 는 45.32%로 나타났다. 4. 모든 계절 공히 개성, 품격, 정연성, 역량성 및 친근감의 인자가 높은 Factor Score를 보여, 삼림경관지의 계절적 공간이미지를 대표하는 인자군으로 나타났으며, 각 공간 이미지의 주인자 및 계절별 이미지 차이를 나타내는 인자는 각지점간 높은 유의성을 보였다. 5. 성별에 따른 Factor Score의 차이는 삼림경관지에 대한 이미지 중 종합평가와 개성 차원에서만 인정되었고, 연령에 따른 차이는 30대 이하와 40대 이상간에 현저한 차이를 보였으며, 학력에 따른 유의성도 나타났다. 직업간의 유의성은 학생과 타 직업간에 나타났다. 직업간의 유의성은 학생과 타 직업간에 현격하게 나타났으나, 개인차를 나타내는 속성적 변수는 상호보완적인 변수기능을 수행하고 있기 때문에 다양한 행동의 설명력있는 이유로 볼 수 없다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.397-397
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• 2022

오늘날 급격한 인구증가 및 도시화로 인해 음식물류 폐기물 발생량이 크게 증가하였으며, 음식물류 폐기물에서 발생되는 음폐수의 적절한 처리방안에 대한 관심이 증가하였다. 혐기성 소화(Anaerobic digestion; AD)는 음폐수의 바람직한 처리방법으로 알려졌지만, 긴 처리기간 및 공정 불안정 등의 문제로 개선이 필요하며, 그 중 기존 AD에 보조 반응조를 추가한 보조 미생물전기화학적 혐기성소화(Auxiliary bioelectrochemical anaerobic digestion; ABEAD)가 적절한 개선방안으로 제시되었다. 하지만 아직 20 L 이상 용량에서의 연구는 이뤄지지 않았으며, 따라서 본 연구에서는 100 L의 용량에서 ABEAD의 성능향상을 평가하고 규모증가에 따른 성능변화를 비교하였다. 반응조는 AD와 ABEAD로 구성되었다. 유효용량 100 L, 유기물부하율 4 kg/m³/d, HRT 20 days 및 중온소화(35℃) 조건으로 운전하였으며, AD는 기계적 교반, ABEAD는 기계적 교반 및 펌프를 통한 bulk 용액 순환이 이뤄졌다. ABEAD의 전극재질은 SUS304를 사용하였고, 0.4V의 전압을 공급하였다. 성능비교는 pH, 휘발성지방산(Volatile fatty acids; VFAs), 유기물제거율 및 메탄 생성량을 비교해 수행하였다. 실험결과 AD는 pH 및 VFAs가 각각 평균 7.37 및 3,880 mg/L, ABEAD는 각각 평균 7.5 및 2,870 mg/L로 VFAs의 빠른 처리를 통해 공정안전성 향상되었고, 유기물제거율 및 메탄생성량의 경우 AD는 각각 평균 65.8 % 및 85.1 L/d, ABEAD는 각각 평균 76.1 % 및 108.1 L/d로 유기물의 빠른 처리 및 메탄전환이 이루어져 비교적 큰 규모에서도 ABEAD의 성능향상이 나타남을 확인하였다. 또한 이전 소규모 연구들과 비교를 통해 규모에 따른 성능향상폭을 비교했을 때에도 큰 차이가 나지 않는 것으로 판단되며, 따라서 ABEAD는 BEAD 기술의 상용화 및 적용에 적합한 것으로 사료된다.