본 연구에서는 강섬유와 FRP 시트에 의한 충격 저항성능 향상 효과를 평가하기 위하여 고속 충격하중을 받는 2방향 RC 슬래브에 대한 유한요소 해석을 수행하였다. 유한요소 해석 프로그램으로는 충격해석에 탁월하다고 알려진 LS-DYNA를 사용하였으며, 실험결과와의 비교를 위하여 핀란드 VTT 연구소에서 수행한 고속 충격 실험과 동일한 조건으로 해석을 수행하였다. 2100×2100×250 mm의 RC 슬래브에 강 (steel)발사체를 통해 충격하중을 가하였으며 발사체의 무게는 47.5kg, 속도는 134.9m/s였다. 본 연구에서는 별도의 재료부재에 대한 충격실험을 통해 해석에 사용할 재료 모델을 검증하였다. 본 해석에서는 SFRC의 비선형적 연화 현상을 모사하기 위해 elastic-plastic hydro model을 적용하였으며, 보통콘크리트와 FRP의 재료모델을 모사하기 위해서 concrete damage model과 orthotropic elastic model을 각각 사용하였다. 해석 결과, 제안된 해석 기법은 충분한 신뢰성을 가지고 있으며, 보강 재료와 보강 기법의 유효성을 평가하는데 효과적으로 적용할 수 있을 것으로 판단된다. 또한 강섬유와 FRP Sheets 보강방법은 고속충격하중에서 우수한 충격 저항 성능을 보여주는 것을 확인하였다.

Concrete floating structures will experience the surface erosions by wave and floaters’ impacts. However, because there exists no standard test method in Korean Industrial standards (KS) related to this issue, proper evaluations have not been able to be performed. To resolve this problem, this study developed a testing apparatus and evaluation methods referring to ASTM C 1138, and series of marine concrete mixtures were evaluated

The purpose of this study is to assess and analyse the environmental impact of construction stage by apartment houses structure using main materials. For this purpose, according to the structure of the apartment houses, by setting the evaluation model and using 6 kinds of main materials, the environmental assessment about 6 environmental category was performed

The impact factor of general road bridges is typically calculated according to Korea Highway Design Code(KHDC) or Design Guidelines For Cable-Supported Bridges in Korea. Above design codes define the impact factor as the function of span length or effective span length. But calculated impadt factors from this function are different to the measured values of long-span bridges such as cable-stayed bridge, suspension bridge. There are several methods to estimate the impact factor of cable supported bridges. In this study, the impact factor of cable-stayed bridges is estimated from dynamic load tests and compared to calculated values from the various design codes.

According to 10CFR50.150, all applicants for new nuclear power plant designs after July 13, 2009 must perform a design-specific assessment of the effects on the facility of the impact of a large, commercial aircraft using realistic analyses. The purpose of the work described in this paper is to evaluate the safety of the APR+ nuclear power plant with respect to the impact by a large commercial aircraft using the missile-target interaction analysis method.

Recently, air-coupled impact-echo (IE) tests for rapid damage detection in concrete structures have been popularly employed, but they typically require an acoustically shielded, high sensitivity, pre-polarized air-pressure sensor. In this study, two types of air-coupled sensors (condenser and dynamic microphones) and one contact sensor (displacement sensor) are evaluated with regard to characterization of delamination damage in a concrete slab using the IE method. The contact and contactless IE tests were carried out over a simulated slab with artificial delaminations. Results show that even the dynamic microphone successfully captures impact-echo signals in a contactless manner and without acoustic shielding.

Vibration resonance tests offer an efficient NDE method to identify and characterize shallow (near-surface) delamination defects that afflict RC structures. However, efficient implementation of effective modal analysis methods for this purpose is hindered by practical testing limitations. This paper studies vibration resonance data from square, rectangular, and circular near-surface delamination defects in concrete using air-coupled impact resonance test.

In this study, we aimed to consider the inspection without destroying the specimen using the Impact Echo Method of nondestructive test using stress wave in an objective manner for detecting defects in concrete members. As a result of estimating the thickness of the concrete slab member using Impact Echo Method under the influence of the result of the stress wave, the average error in the 7.49% confirmed the applicability. In addition, we can check the possibility of data acquisition and construction of concrete structures for the construction of the diagnosis system

Part of the domestic construction practice and non-destructive inspection technology world level is often inadequate to provide the test results to serve as a basis for evaluating the safety of the structure. Therefore, in this study, is intended to provide basic data for legislation nondestructive inspection in Japan, estimates the size of the column using a technique reverberation impact manufactured column member or this purpose. 3% maximum error rate, the result was 1% minimum error rate. The average error rate is 1.6%, revealed as well as the size of the columns that have been measured

본 연구는 기업 이미지를 형성하는 요소인 ‘안정성’, ‘신뢰성’, ‘친근성’, ‘명성’, ‘사회공헌’을 바탕으로 기업 이미지의 구성요인인 ‘이미지 연상 강도’, ‘이미지 호의성’, ‘이미지 차별성’이 개별 브랜드 신뢰에 어떠한 영향을 미치는가를 살펴보았으며 기업 이미지가 소비자 대안평가 시 지각된 위험과 구매의도에 직접적인 인과관계가 있는지를 알아보았다. 그리고 개별 브랜드 신뢰가 소비자의 브랜드 대안평가 시 지각된 위험을 낮춰주는가와 실제 구매의도를 높여주는가를 연구하였다. 가설 검증은 증권회사 자산관리서비스를 이용하는 거래고객 263명의 설문을 토대로 구조방정식모델을 통해 실증 분석하였다. 결론적으로 개별 브랜드 가치를 강화하기 위해서는 기업 이미지의 제고가 선행되어야 하며 브랜드 신뢰를 바탕으로 소비자 대안평가의 상대적 우위를 점유하는 것이 무엇보다 중요하다고 할 수 있다. 본 연구는 향후 자산관리서비스 시장에서 증권회사와 고객과의 관계 형성에 이용될 수 있는 브랜드 관리의 구성적 모델을 제공하고 보다 지속적이고 장기적인 형태로 발전시킬 수 있는 평가 기준으로 활용할 수 있을 것이다.

여성가족부는 2011년 10월부터 온라인게임에 대한 셧다운제를 실시하였다. 셧다운제는 게임 과몰입을 방지하고 청소년의 수면권을 보호하는 것을 정책 목표로 내세웠지만, 셧다운제가 과연 청소년들의 게임 과몰입을 해결할 수 있는지, 정책의 실효성 있는 집행이 가능한지에 대해 많은 반론이 존재하였다. 본 연구는 게이머와 비게이머간에 셧다운제 정책 효과에 대한 인식 차이가 존재하는지, 그리고 셧다운제의 실시가 게이머와 비게이머의 정부 신뢰에 대한 인식에 어떠한 영향을 미치었는지를 살펴보도록 하였다. 설문 조사 결과, 게이머는 셧다운제에 대해 부정적으로 보고 정부신뢰가 감소되었으며, 비게이머들은 셧다운제를 긍정적으로 보고 정부신뢰가 증가되는 효과가 존재하였다. 즉 셧다운제는 비게이머들이 정책효과를 믿으면서 실시한 정책으로, 막상 정책대상자들인 게이머들은 정책 효과를 인정하지 않는 성격을 지니는 정책으로서의 특성을 지닌다.

This paper studies the problem of tracking a re-entry vehicle (RV) in order to predict its impact point on the ground. Re-entry target dynamics combined with super-high speed has a complex non-linearity due to ballistic coefficient variations. However, it is difficult to construct a database for the ballistic coefficient of a unknown vehicle for a wide range of variations, thus the reliability of target tracking performance cannot be guaranteed if accurate ballistic coefficient estimation is not achieved. Various techniques for ballistic coefficient estimation have been previously proposed, but limitations exist for the estimation of non-linear parts accurately without obtaining prior information. In this paper we propose the ballistic coefficient β model-based interacting multiple model-extended Kalman filter (β-IMM-EKF) for precise tracking of an RV. To evaluate the performance, other ballistic coefficient model based filters, which are gamma augmented filter, gamma bootstrapped filter were compared and assessed with the proposed β-IMM-EKF for precise tracking of an RV.

낙동강 미래 기후변화 시나리오 추출을 위해 CGHR(T63) 모형과 A1B 온실가스 배출시나리오를 통계적 규모내림방법으로 대상유역의 규모로 축소·변환한 후, 수문·수질의 거동변화 등의 영향을 모의하기 위해 SS와 T-P를 대상으로 SWAT 모델을 적용하였다. 과거 30년 자료와 비교한 결과, 지표유출은 지역에 따라 최대 60%까지, 오염배출 부하는 TSS와 T-P의 경우 각각 35∼45%, 5∼20% 정도 변화되어, 미래 기후변화로 인한 지표유출과 오염부하 배출은 향후 뚜렷한 증가가 예상된다. 또한, 그 증가경향은 낙동강 하류지역보다 상류지역에 크게 나타나며 계절별로는 겨울과 봄철의 증가가 크고 먼 미래로 갈수록 증가하는 반면, 여름과 가을철에는 먼 미래로 갈수록 증가율이 감소하는 경향을 나타내어 갈수기 지표수 수질에 부정적인 영향을 미칠 것으로 예측된다.

In this study, specimens were produced to reach design standard strengths 40, 50 and 60MPa on age 28 days to evaluate the usability of high strength recycled aggregate concrete and the applicability of compressive strength by Impact Echo method and numerical analysis, and after 0, 30, 50 and 100% recycled coarse aggregates were substituted and mixed into each combination, totally 12 combinations were set. And, through compressive strength test, Impact Echo method, shock reverberation technique and numerical analysis on 1, 3, 7 and 28 days of age

The objective of this study is to assess the structural response and impact energy absorption characteristics of reinforced concrete (RC) and steel plate concrete (SC) barrier walls under missile impact loading considered in the design of NPP (nuclear power plant)'s facilities. The study considered the barrier wall response under external tornado-generated missiles (e.g., steel pipe and automobiles).

The objective of this study is to develop the reinforcing design method of the NPP (nuclear power plant)'s steel plate concrete (SC) wall for enhancement of impact resistance capacity under the aircraft and missile impact loading considered in the design of NPP's facilities. This study investigated the effects of the several parameters that can affect impact resistance capacity of SC wall using finite element analysis method.(e.g., thickness of concrete and steel plate, material strength of concrete and steel, and other reinforcing design method).

The purpose of this study is to develop structral technologies on the lightweight composite slab systems with sound reduction layers in the modular house. In this study, two kinds of slabs with minimum thickness was suggested reducing the floor impact sound. In order to evaluate the structural performance, the flexural strenth tests were carried out on the one-way full scale specimens. From the results of test, we know that the proposed slabs had ductile behavior and would be safe sufficiently.

When a floor falls onto the floor below, the impulse transmitted to the lower system results in considerable deformation in the impacted floor. In this paper, a linear static progressive collapse analysis procedure was developed considering the impact of failed members. The impact loads computed from various simplified methods were calibrated with FEM analysis results. The analysis procedure was applied to a moment frame and a braced frame, and the results were compared with those obtained without considering impact load.

This research evaluated the environmental impact of waste film used in the farming industry which is subject to voluntary agreement by Waste Charge System using Life Cycle Assessment (LCA). When analyzing the environmental scores applying weighted values, production of raw materials, production of goods and disposal had nearly 73%, 15% and 11% of contribution to the environmental impact and also, amongst impact categories, resource depletion and global warming had 63% and 32% of contribution respectively. For resource depletion which had the highest contribution, production of raw materials, production of goods and disposal occupied around 86%, 9% and 4% of it, and the impact category of resource depletion that belongs to production of raw materials, accounted for about 54% of the whole environmental score. Here, over 95% of it was caused by crude oil. When investigating the contribution of each phase to global warming that is the key issue of low carbon green growth, production of raw materials, production of goods and disposal had respectively, 45%, 28% and 27% of contribution. As the result, production of goods and disposal had higher contributions than resource depletion. The entire contribution of production of goods and disposal to global warming was about 17%, and it is predicted that it would bring a huge impact, considering the possibility of establishing improvement plans. In the production of goods, electricity consumed was the main cause of global warming, and electricity used in the recycling process and incineration occupied approximately 52% and 42% of the disposal stage. In conclusion, we should pay attention to energy used in the production of goods and recycling for improving an environmental competitiveness of goods, and reduction of energy would be able to satisfy economic feasibility and environmental efficiency of the whole process of agricultural PE film.

Quantitative analysis of food waste, especially food loss, has received worldwide attention in the viewpoint of efficient food supply and consumption. Food waste generation characteristics expressed as the place and the quantity are influenced by food consumption styles. Food consumption styles can be classified into Meals at home, Convenience meals, and Meals outside the home. And also food waste was classified into food loss and inedible portion, here, the two have different meaning in terms of reason for generation and the social meaning. Using Material Flow Analysis (MFA), food and food loss flow of Japan in 2008 was drawn, and food waste generation rate by food consumption styles were calculated. First result is that meat, sea foods, and fat are much consumed in externalized meal (convenience meals or meals outside the home). After allocating foodstuffs to each food consumption style, we made a flow diagram of food waste. In wholistic viewpoint, it indicated that food loss are generated mostly in households and restaurants, which is caused by consumer's carelessness. In the viewpoint of food consumption style, convenience meals has the lowest level on total food loss including consumer sector and industrial sector. However, in only industrial part, convenience meals has the highest level on food loss, which means convenience meals increase food loss in supply chain before reaching consumer. Social changes have driven the increase of convenience meals, but also food waste weight-charged system, which is new policy in Korea, may cause the increase of pre-cooked food consumption in households and restaurants. Therefore, it is necessary to do monitor the change of food consumption styles and whole sectors of food waste generation sectors. Material Flow Analysis can be considered as a useful tool to monitor the change and assess the performance by the system from a holistic perspective.