• 수산해양기술연구
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• 제48권1호
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• pp.82-90
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• 2012

Four different buildings having various wall construction are analyzed for the effect of wall mass on the thermal performance and inside building air and wall temperature transient and also for calculating the energy consumption load. This analytical study was motivated by the experimental work of Burch et al. An analytical solution of one-dimensional, linear, partial differential equations is obtained using the Laplace transform method, Bromwich and modified Bromwich contour method. A simple dynamic model using steady state analysis as simplified methods is developed and results of energy consumption loads are compared with results obtained using the analytical solution. Typical Meteorological Year data are processed to yield hourly average monthly values. This study is conducted using weather data from two different locations in Korea: Daegu having severe weather in summer and winter and Jeju having mild weather almost all year round. There is a significant wall mass effect on the thermal performance of a building in mild weather condition. Buildings of heavyweight construction with insulation show the highest comfort level in mild weather condition. A proportional controller provides the higher comfort level in comparison with buildings using on-off controller. The steady state analysis gives an accurate estimate of energy load for all types of construction. Finally, it appears that both mass and wall insulation are important factors in the thermal performance of buildings, but their relative merits should be decided in each building by a strict analysis of the building layout, weather conditions and site condition.

• 한국건설관리학회논문집
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• 제5권6호
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• pp.80-89
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• 2004

건설생산성에 영향을 미치는 많은 요소 중에서, 외부공사가 많은 건축공사는 기후의 영향을 많이 받는다. 지난 30년에 걸쳐 기후요소와 건설생산성간의 관계에 대한 많은 연구가 진행되어 왔지만, 대한민국의 지리적 특징을 잘 반영하는 연구는 미비하였다. 본 논문에서는 같은 유형의 공동주택 4개동($16\~18$층)의 데이터를 이용하여 골조공사의 건설생산성과 5가지 기후요소(온도, 습도, 낮 길이, 강수, 풍속)와의 관계를 단순회귀분석과 다중회귀분석을 통해 규명하였다. 단순회귀분석 결과, 기후요소 중 온도, 낮 길이가 건설생산성에 가장 큰 영향을 미치는 것으로 나타났고, 다중회귀분석으로부터는 기후요소에 의해 생산성을 예측할 수 있는 회귀식을 도출하였으며, 이러한 분석결과에 대한 검증과 활용 방안을 제시하였다. 본 연구의 결과는 공사관리의 기획단계 혹은 공정관리의 기초 자료로 사용될 수 있을 것으로 기대된다.

• 천문학회보
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• 제42권2호
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• pp.62.3-63
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• 2017

The Mars Atmosphere and Volatile (MAVEN) mission has been providing valuable information on the atmospheric loss of Mars since its launch in November 2013. The Neutral Gass and Ion Mass Spectrometer (NGIMS) onboard MAVEN, was developed to analyze the composition of the Martian upper atmospheric neutrals and ions depending on various space weather conditions. We investigate a variation of upper atmospheric ion densities depending on the interplanetary coronal mass ejections (ICMEs). It is known that the Mars has a very weak global magnetic field, so upper atmosphere of Mars has been strongly affected by the solar activities. Meanwhile, a strong crustal magnetic field exists on local surfaces, so they also have a compensating effect on the upper atmospheric loss outside the Mars. The weak crustal field has an influence up to 200km altitude, but on a strong field region, especially east longitude of $180^{\circ}$ and latitude of $-50^{\circ}$, they have an influence over 1,400km altitude. In this paper, we investigated which is more dominant between the crustal field effect and the ICME effect to the atmospheric loss. At 400km altitude, the ion density over the strong crustal field region did not show a significant variation despite of ICME event. However, over the other areas, the variation associated with ICME event is far more overwhelming.

• 한국자동차공학회논문집
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• 제18권4호
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• pp.121-126
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• 2010

The automotive weather strip has functions of isolating of water, dust, noise and vibration from outside. To achieve good sealing performance, weather strip should be designed to have the high contact force and wide contact area. However, these design causes excessive permanent deformation of weather strip. The causes of permanent deformation is generally explained to be the chemical material detrioration and physical variation and cyclic loading, etc. This paper introduces a numerical method to predict the permanent deformation using the time dependent viscoelastic model which is represented by Prony series in ABAQUS. Uniaxial tension and creep tests were conducted to obtain the material data. And the lab. test for the permanent deformation was accelerated during shorter time, 300 hours. The permanent deformation of weather strip was successfully predicted under the different loading conditions and different section shapes using the suggested numerical process.

• 대기
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• 제24권2호
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• pp.265-281
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• 2014

Currently, Korea is developing a Cheollian follow-on satellite program, named as Geostationary Korea Multipurpose Satellite 2 (GK-2), which consists of two satellites. One satellite (GK-2A) is dedicated to the meterological mission, while the second one (GK-2B) hosts two main payloads for the ocean and environmental application. As GK-2A is dedicated to the meteorological mission unlike Cheollian, there have been discussions on the possibility of transferring the responsibilities of the GK-2A program to the Korea Meteorological Administration. To help resolve any consumptive disputes or to find an efficient way for the GK-2A program, the events happened after the successful launch of the first meteorological satellite TIROS-1 in the U.S. in April 1960 are investigated. With the successful demonstration of usefulness of TIROS-1 for the meteorological applications, organizations such as the Weather Bureau and the Department of Defense, responsible for the real time application of the TIROS 1 data, strongly requested for an operational meteorological satellite program which resulted in the plan for the National Operational Meteorological Satellite System (NOMSS). The plan was strongly supported by Kennedy Adminstration and was put forwarded for the new program under the responsibility of Weather Bureau to the Congress. However, the responsible Committee on Science and Aeronautics sided with NASA and requested major revision of the responsibility. Due to many unfavorable conditions, Weather Bureau accepted the requests and signed with NASA on the agreement for the operational meteorological satellite. However, with the delay of Nimbus satellite which is planned to be used for the prototype of the operational satellite and changes of the unfavorable situations, the Weather Bureau could draw a second agreement with NASA. The new agreement reflected most propositions requested by the Weather Bureau for the NOMSS plan. Until now the second agreement is regarded as the basic principles for the operational meteorological satellite program in the U.S. This study investigates the backgrounds and processes of the second agreement and its implications for the GK-2 program.

• 한국기후변화학회지
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• 제4권4호
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• pp.385-395
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• 2013

본 논문에서는 이동성이 용이한 스마트기기에서 웨비게이션(Weavigation) 서비스를 이용할 수 있도록 기상플랫폼 및 서비스 구현을 목표로 한다. 기존에 개발된 TPEG(Transport Protocol Expert Group) 기반의 웨비게이션 서비스는 전용 단말의 필요, DMB 통신방식 및 서비스 확장성 등에서 한계가 존재한다. 본 논문에서는 일반 사용자의 스마트기기 내비게이션에 적합한 실시간 기상정보를 분석, 가공, 저장, 제공할 수 있는 표준화된 "웨비게이션용 기상정보 제공 플랫폼"을 개발하였으며, 또한 범용 스마트기기에서 Open API를 사용하여 쉽게 다양한 서비스 개발이 가능하도록 웨비게이션용 Open API 개발과 이를 활용한 웨비게이션 서비스를 구현하여 자연재해 위험지구 정보를 이용한 위험구간 예측정보 안내서비스 연구 결과를 소개한다.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.397-402
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• 2013

In super-tall building construction projects, schedule risk factors which vertically change and are not found in the low and middle-rise building construction influence duration of a project by vertical attribute; and it makes hard to estimate activity or overall duration of a construction project. However, the existing duration estimating methods, that are based on quantity and productivity assuming activities of the same work item have the same risk and duration regardless of operation space, are not able to consider the schedule risk factors which change by the altitude of operation space. Therefore, in order to advance accuracy of duration estimation of super-tall building projects, the degree of changes of these risk factors according to altitude should be analyzed and incorporated into a duration estimating method. This research proposes a simulation model using Monte Carlo method for estimating activity duration incorporating schedule risk factors by weather conditions in a super-tall building. The research process is as follows. Firstly, the schedule risk factors in super-tall building are identified through literature and expert reviews, and occurrence of non-working days at high altitude by weather condition is identified as one of the critical schedule risk factors. Secondly, a calculating method of the vertical distributions of the weather factors such as temperature and wind speed is analyzed through literature reviews. Then, a probability distribution of the weather factors is developed using the weather database of the past decade. Thirdly, a simulation model and algorithms for estimating non-working days and duration of each activity is developed using Monte-Carlo method. Finally, sensitivity analysis and a case study are carried out for the validation of the proposed model.

• Corrosion Science and Technology
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• 제2권5호
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• pp.207-211
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• 2003

The weather resistance of five coatings systems based on alkyd, chlorinated rubber, epoxy, polyurethane and fluoropolymer were studied by natural exposure test and accelerated test. The coatings were exposed at Hanoi station with urban industry atmosphere and at Baichay station with marine atmosphere. The degradation of coatings was evaluated by gloss measurement and surface analysis by scanning electronic microscopy. The results obtained show that among coatings tested the gloss of polyurethane and fluoropolymer coatings remained highly and those of alkyd, chlorinated rubber and epoxy coatings were very low after two years of atmospheric exposure. Under accelerating conditions the gloss of fluoropolymer coatings remained highly after 80 cycles of testing. By comparison with accelerating test in UV-condensation chamber the conditions at atmospheric stations are more aggressive.

• 한국산업정보학회논문지
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• 제20권3호
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• pp.87-93
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• 2015

졸음 운전 등 운전자의 상태 변화에 따른 자동차 사고가 급증하고 있으며 이를 방지하기 위한 시스템 구축 및 운전자의 상태를 판단하는 알고리즘 개발이 요구되어 지고 있다. 본 논문에서는 모의 주행 시스템을 통한 운전자의 심박변이도, 산호 포화도 (SPO2), 체온을 측정하여 운전자의 상태를 알려 주는 실험을 수행하였다. 즉, 심박변이도 (Heart rate variability, HRV) 분석을 위해 운전자의 심전도(Electrocardiogram, ECG) 신호를 획득 한 후 심전도 P,QRS, T 파형 중 R peak 을 자동으로 검출하였고 이를 통해 구한 R-R interval을 이용하여 HRV의 주요 파라메타를 시간영역(time domain)으로 해석하여 작업 환경에 따른 운전자의 상태를 비교 분석하였다.

• 한국도로학회논문집
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• 제15권6호
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• pp.17-23
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• 2013

PURPOSES : This study aimed to measure the skid resistance of the sidewalk in order to find out the relationship between different surface types and skid resistance. By using British Pendulum Tester, skid resistance of sidewalk was measured in a wet after snow-melt, sludgy, and snowy conditions. METHODS : The skid resistance was measured on surfaces including Concrete Interlocking Block Paving, Colour Asphalt Pavement, Granite Block Paving, Manhole, and Tactile Paving for Visually Impaired. Five trials at each measurement were made, and the average and standard deviation were derived. RESULTS : The skid resistance measured in wet after snow-melt, sludgy, and snowy conditions for the various surface types are summarized and compared. Reduction rates of skid resistance of sludgy and snowy against wet after snow-melt are also analysed. The skid resistance variation between measurement points which mimic pedestrian route in study site are analysed to check out the consistency of the skid resistance along the sidewalk. CONCLUSIONS : The study concluded that the skid resistance of sidewalk surfaces varied depending on the surface types and weather conditions. Secondly, reduction rates of skid resistance according to weather changes are varied depending on the surface types, Thirdly, consistency of skid resistance along the pedestrian route is hardly acquired in the study site at least. So, future study on the consistency evaluation for skid resistance along sidewalk is strongly recommended.