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        검색결과 1,728

        1381.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        콘크리트 구조물이 화재 손상을 입을 경우 노출온도 및 지속시간에 따라 구조물의 심각한 성능 저하를 야기하며, 콘크리트의 재료 물성 저하를 수반한다. 화재 손상을 입은 콘크리트 구조물의 재사용여부 및 보수보강 판단을 위해서는 손상 직후 및 재양생 조건에 따른 주요 손상 부위의 면밀한 손상 평가가 필요하다. 본 연구에서는 재양생 조건에 따른 화재 손상을 입은 콘크리트의 재료물성 회복에 관한 실험적 연구 를 수행하였다. 화재 손상을 입은 콘크리트 시편을 상대습도 및 재양생 기간을 달리한 재양생 조건을 적용하였으며, 충격공진기법을 도입하여 콘크리트 시편의 화재 손상 전후 및 재양생 이후의 동탄성계수를 측정하여 손상 정도를 평가하였다. 측정된 결과로부터 재양생 조건 중 높은 상 대습도 조건에서 지배적으로 재료물성의 회복이 발생하였다. 추가적으로 콘크리트 시편의 동탄성계수 및 인장강도의 직접적인 비교 및 선형 회귀분석을 수행하여 재양생 조건에 따른 영향을 분석하였으며, 이를 토대로 높은 습도 조건에서 동탄성계수의 회복이 인장강도에 비해 두드 러지게 나타남을 확인하였다.
        1382.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        본 연구는 가나의 비료 보조금 정책(Fertilizer subsidy program: FSP)의 농업 생산성에 대한 영향을 분석하였다. 가나의 군(district) 지역 수준의 농업 생산량 및 투입요소에 대한 자료를 사용하여, FSP 도입 이전과 FSP 도입 이후의 농업 생산성을 계측하였다. 지역적으로 상이한 수준의 농업 생산성을 반영하기 위한 지리적가중회귀(GWR)모형을 사용하여 계측 의 오류를 줄이고 공간이질성을 고려하였다. 추정 결과를 바탕으로 ArcMap을 이용하여 생산성을 지도로 시각화 한 자료를 살펴보면, FSP 도입 이후 농업 생산성이 전반적으로 개선되었으며 그 중에서도 생산성이 크게 향상된 지역을 특정할 수 있다. 이러한 공간적 변화는 FSP의 지역적 할당의 효율성 증진을 위한 의사결정 자료로 이용 가능하며, 국내 ODA 추진기관에 서 농업 지도 및 지원을 위해 유용한 정보로 사용할 수 있다.
        1384.
        2017.09 서비스 종료(열람 제한)
        In this study, collision analysis of overlay concrete median barrier under truck load was conducted depending on location of rebar and shear key. Obtained results indicates that the impact resistances of overlay concrete median barrier was improved as the rebar and shear keys are more closed to the top surface of the CMB.
        1385.
        2017.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In the current competitive marketplace of real estate business, tenant satisfaction measurement is one of the important indicators to monitor competitiveness in industrial property development. It has become an industry standard to measure tenant satisfaction, commonly called customer satisfaction. Customer satisfaction has become the widely used metric to manage customer loyalty (Keiningham, Gupta, Aksoy, & Buoye, 2014). The aim of this research is to determine the impact of property management services on tenants’ satisfaction with the three identified variables i.e. facility management, perceived quality and lease management. Structural equation modeling (SEM) is applied to build constructs and test the hypotheses with the collected survey samples. Of the three variables, facility management is the most influential factor that leads to tenant satisfaction with industrial buildings. Next, perceived quality is another important factor that contributes to tenants’ pleasure. Compared with these two, lease management fares worse, having the least extensive effect on tenant satisfaction, and could be disregarded. The ultimate impact of tenant satisfaction is about tenant retention and recommendation. The overall findings of this research will potentially help real estate developers to develop a better property management system, leasing program and tenant retention strategy.
        1386.
        2017.08 KCI 등재 서비스 종료(열람 제한)
        표준 중량 충격원의 실제 충격원 재현성에 대한 논란이 있음에도 현재 기준에서는 뱅머신 방식만 사용하고 있다. 현행 기준의 평가 방법 및 등급 기준이 충격원 특성을 고려하지 못하고 있어 충격원의 선택에 따라 바닥충격음 차단 성능 등급에 차이가 발생하기 때문이다. 본 연구는 충격원 특성 외에 바닥 진동 거동 특성을 함께 고려한 현행 기준의 바닥충격음 평가 방법 고찰을 목적으로 한다. 공동주택 mock-up 실험 동에서 표준 중량 충격원과 실충격원에 대하여 바닥충격음을 측정하고 이를 이용하여 해외 평가 방법과 우리나라의 평가 방법을 비교 검토하 였다. 또한 현행 바닥충격음 평가 기준의 대상 주파수 범위를 벗어나는 저주파수 대역의 음압레벨은 네텔란드의 저주파 소음 인지 곡선과 국내 연구자가 제안한 저주파 소음 기준안을 이용하여 평가하였다. 그 결과 기준 및 평가 산정 방법에 따라 성능 평가 결과가 상이하며, 바닥 진동의 지배 주파수 범위에서 모든 충격원에 대한 바닥충격음 가청 소음으로 인식하여 성가시게 느낄 가능성이 매우 크다. 현행 평가 기준의 단일수치 평가량 산정 방법은 충격원에 따라 상이한 음압레벨 스펙트럼 특성을 제대로 반영하지 못하며, 바닥의 진동 거동 지배 주파수를 포함하는 저주 파수 대역의 음압레벨을 고려하지 않고 있어 바닥충격음에 대한 평가 결과와 사람의 인지 수준에 차이가 발생할 수 있다. 따라서 충격원에 따른 음압레벨의 스펙트럼 특성과 저주파수 대역의 음압레벨을 반영할 수 있도록 현행 기준의 평가 방법을 보완할 필요가 있다.
        1387.
        2017.08 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 HMD(Head Mounted Display)를 가지고 Walk-through의 이동시뮬레이션에 대한 평가를 실시하였다. 구체적으로는 VR공간 주변에 배치된 오브젝트 밀집정도(밀도)의 변화가 심리적 이동거리, 이동속도, 이동시간에 어떠한 영향을 미치는지 알아보았다. 연구결과 첫째, 실험 조건 (저밀도, 중밀도, 고밀도)에 있어 조건간의 차이는 모두 유의미하였다. 둘째, 주변 오브젝트의 밀도가 높아질수록 이동시간, 이동속도, 이동거리가 기본조건과 비교하여 평균점이 높게 나타났다. 셋째, 주변의 오브젝트가 VR공간의 이동시뮬레이션에 있어 시간, 속도, 거리의 감각을 향상 시키는 것을 확인하였다.
        1388.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        Industrial symbiosis (IS) activities within an industrial complex can enhance environmental and economic efficiencies. This study proposed a simplified life cycle assessment (LCA) methodology as an effective tool with which to evaluate the reduction of environmental impact of IS activities. In this method, the variation of resources and energy consumptions before and after IS activities are proposed to simply evaluate its lifecycle environmental impacts. The simplified LCA was applied to an IS case between an industrial waste incineration plant and a steam production plant of a paper mill firm in the metropolitan city Ulsan. The system boundary and inventory were set for this IS, and an environmental impact assessment was carried out by standard and proposed LCA methods. The results showed that the environmental impacts after IS decreased in all impact categories with regard to the consumption reduction of boiler fuel used at the paper mill. Furthermore, the performance of environmental improvement activities such as IS can be simply evaluated by only considering the input and output changes in the environmental improvement activities. In this IS case study, the environmental impact was decreased by 11.7% (weighted impact base). This was due to the utilization of waste heat generated from an incineration plant in the process of the paper mill firm.
        1389.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        We investigated on the proper combination of physical parameterization schemes of RegCM4.0 for the simulation of regional climate over CORDEX-East Asia Phase 2 domain. Based on the Lee(2016)’s sensitivity experiments for the four combination using two land surface schemes and two cumulus parameterization schemes during 5 years (1979-1983), we selected the two combinations (CE: CLM+Emanuel and BG: BATS+Grell). The ERA-Interim was used as lateral boundary data of RegCM4.0 for the two experiments during 25 years (1981-2005). Simulation skills of temperature were similar in the two combination of physical processes irrespective of seasons and locations. However, there were a substantial differences in the simulation skills of precipitation according to the combination of physical processes, which were better in CE than BG combination. In general, the CE combination better simulated the precipitation characteristics in July and August over South Korea than BG combination, in terms of frequency and amount of precipitation according to the intensity. The superior skills of CE in simulating precipitation over South Korea can be related to the better simulation of seasonal march of the East Asian summer monsoon including the location and intensity of the North Pacific high pressure system than BG. The results suggested that the CE combination can simulate the climate characteristics in the CORDEX East Asia Phase 2 region better than the BG combination.
        1390.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to extract climate factors affecting sweet persimmon yield by growth period and estimate the rate of future sweet persimmon yield using data of production and cultivation area of sweet persimmon and climate data for 1998-2015. During the analysis period, the cultivation area of sweet persimmon in Gyeongnam has been consistently decreasing, but sweet persimmon yield has increased. Climate factors that have statistically significant effects on sweet persimmon yield are mean temperature, maximum temperature, precipitation, precipitation days, and sunshine hours. The sweet persimmon yield is a statistically positively correlated with temperature and sunshine hours and negatively correlated with precipitation during the flowering period (April to May). The sweet persimmon yield is statistically positively correlated with precipitation in the growing period (June to August) and negatively correlated with temperature in maturity period (September to November). Future sweet persimmon yield is estimated to have a steadily decreasing rate of change in future climate change scenarios, RCP4.5 and RCP8.5.
        1391.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        Purpose - The total amount of advanced Corporate Pension Insurance products exceed 148 trillion Korean Won at the end of 2016. For a firm with over 300 employees, when a bill on compulsion of introduction of Corporate Pension Insurance products, currently pending in court, is passed, Corporate Pension shall be an essential. The findings of the paper will provide a guideline for understanding on firm's attributes and its effects towards introduction of Corporate Pension Insurance products. Research design, data, and methodology – The data were collected using statistics of employer panel survey from Korea Labour Institute in 2013. The study analyses a sample survey on 1,775 outstanding enterprises and their HR department among whole corporations in Korea. For analysis of data, empirical testing by Logistic Regression was utilized. Results – As an outcome of empirical testing, variables on share of regular employees and the aged employees in over 50's generates a significant statistical meaning. It eventually gives a great impact on purchase of Corporate Pension scheme. Moreover, variables on corporate financial statement, current sales, current net income, total amount of the debts, labor cost per person also has a vital influence on introduction of Corporate Pension Insurance products. Lastly, variables on firm's labor relationship have no effect except for the execution or non-execution of HR consulting. Meanwhile, Variables affecting a choice on pension schemes types among firm's attributes are a share of regular employees, current net income, execution or non-execution of HR consulting etc. These variables represents a statistical implication. According to their each features, they prefer DB or DC plan. Conclusions – Introduction of corporate pension scheme is apposite to contemporary Korea's situation entering a hyper-aging society and firms with a high share of regular employees, the weight of aging, current sales, current net income and labor cost per person are exceedingly active in purchasing Corporate Pension Insurance products. However, after the introduction of corporate pension scheme, firms which has an implementation of consultation on human resource management, flexible benefits plan, job security and welfare system prefer DC plan whereas from financial perspective firms with high net income prefer DB plan.
        1392.
        2017.05 KCI 등재 서비스 종료(열람 제한)
        In order to simulate a typhoon precisely, the satellite observation data has been assimilated using WRF (Weather Research and Forecasting model) three-Dimensional Variational (3DVAR) data assimilation system. The observation data used in 3DVAR was GPS Radio Occultation (GPS-RO) data which is loaded on Low-Earth Orbit (LEO) satellite. The refractivity of Earth is deduced by temperature, pressure, and water vapor. GPS-RO data can be obtained with this refractivity when the satellite passes the limb position with respect to its original orbit. In this paper, two typhoon cases were simulated to examine the characteristics of data assimilation. One had been occurred in the Western Pacific from 16 to 25 October, 2015, and the other had affected Korean Peninsula from 22 to 29 August, 2012. In the simulation results, the typhoon track between background (BGR) and assimilation (3DV) run were significantly different when the track appeared to be rapidly change. The surface wind speed showed large difference for the long forecasting time because the GPS-RO data contained much information in the upper level, and it took a time to impact on the surface wind. Along with the modified typhoon track, the differences in the horizontal distribution of accumulated rain rate was remarkable with the range of 600~500 mm. During 7 days, we estimated the characteristics between daily assimilated simulation (3DV) and initial time assimilation (3DV_7). Because 3DV_7 demonstrated the accurate track of typhoon and its meteorological variables, the differences in two experiments have found to be insignificant. Using observed rain rate data at 79 surface observatories, the statistical analysis has been carried on for the evaluation of quantitative improvement. Although all experiments showed underestimated rain amount because of low model resolution (27 km), the reduced Mean Bias and Root-Mean-Square Error were found to be 2.92 mm and 4.53 mm, respectively.
        1393.
        2017.05 KCI 등재 서비스 종료(열람 제한)
        Recently IPCC (International Panel on Climate Change, 2007) pointed out that global warming is a certain ongoing process on the earth, due to which water resources management is becoming one of the most difficult tasks with the frequent occurrences of extreme floods and droughts. In this study we made runoff predictions for several control points in the Geum River by using the watershed runoff model, SSARR (Streamflow Synthesis and Reservoir Regulation Model), with daily RCP 4.5 and RCP 8.5 scenarios for 100 year from 1st Jan 2006 to 31st Dec 2100 at the resolution of 1 km given by Climate Change Information Center. As a result of, the Geum River Basin is predicted to be a constant flow increases, and it showed a variation in the water circulation system. Thus, it was found that the different seasonality occurred.
        1394.
        2017.04 KCI 등재 서비스 종료(열람 제한)
        Slag and coal ash were selected to evaluate the recyclability of waste generated during the heat treatment processes. A list of waste types and recyclable types of the two wastes were identified. A recycling environmental hazardous assessment was reviewed step by step. In addition, the hazardous properties of slag and coal ash were investigated, and the chemical components, leaching, and content of harmful substances in the waste were analyzed. The two selected wastes were classified as general wastes. As a result of chemical analysis with XRF, the two wastes did not produce toxic gases in contact with water and show leaching toxicity from the analysis of harmful substances. In addition, waste is often brought into contact with the soil when recycled, so the content of slag and coal ash is analyzed and compared with the 2 region standard of soil; two samples were within the standard. Therefore, the surveyed wastes can be recycled in non-matrix contact types and the recycling purpose and method permitted by the new law is excluded from the recycling environmental hazardous assessment. However, to recycle wastes for new uses, the recycling environmental hazardous assessment is required.
        1395.
        2017.04 서비스 종료(열람 제한)
        This research developed the fiber pullout impact test machine to investigate interfacial bond strength between fiber and cement based matrix under high velocity. To achieve the goal, firstly the existing pullout test machines were investigated. And then, these drawback were comprehended. Finally, Fiber pullout impact test machine base on strain energy frame impact machine was proposed.
        1396.
        2017.04 서비스 종료(열람 제한)
        This study was evaluated dynamic impact fracture behaviour of 80 MPa sprayed HPFRCC by Gas-gun test as a part of the research for development of sprayed HPFRCC for protection and blast resistant of existing structures.
        1397.
        2017.04 서비스 종료(열람 제한)
        This study performed gas-gun propelled projectile impact tests with high strength steel fiber reinforced concrete. Also, from the impact tests, failure modes and protection performances of HIgh Performance Concrete which is reinforced by steel fibers were assessed. High strength steel fiber reinforced concrete showed excellent protection performances against impact loads.
        1398.
        2017.04 서비스 종료(열람 제한)
        In this study, preliminary analytical study on the middle scale impact test of SC(steel plate concrete) walls were carried out to evaluate the impact resistance performance of SC walls subjected to missile impact load. A total of 15 middle-scale impact tests will be carried out to investigate the impact behavior of SC walls. Pre-test impact analysis for all test cases were performed to decide the initial impact velocity. Calibrations of the analytical parameter were performed using preliminary test results.
        1399.
        2017.04 서비스 종료(열람 제한)
        For the evaluation of load carrying capacity of continuous bridges, the testing target span should be selected where peak impact factor can be expected. In this paper, two and three continuous bridges with equal span length are considered and the moving vehicle load analysis is performed. All possible vehicle speeds are applied to the bridges and the peak impact factors obtained for each span are investigated. From the results, the maximum peak impact factors are developed at the middle of the first span to the direction of vehicle moving.
        1400.
        2017.04 서비스 종료(열람 제한)
        Recently, the velocity of vehicle in highway has been increased due to improved driving environment. Unfortunately, the impact resistance of present concrete median barrier is not enough for increased impact severity due to increased velocity, furthermore, these increased velocity occurs another secondary accidents due to the concrete fragmentation. Therefore, in this study, the evaluation of impact resistance for developed concrete median barrier was performed with shock absorber.