70~80년대 급속한 경제성장기에 구축된 사회자본시설은 최근에 와서 노후화가 급속히 진행되 면서 기존구조물에 대한 유지관리와 활용방안에 대해서 관심이 높다. 지금까지 콘크리트 구조 물의 유지관리에 대해서는 관심이 높은 분야는 아니였지만, 적절하고도 전략적인 유지 관리를 실시하기 위해서는 항상 콘크리트 구조물의 상태에 대해서 주의하고 여러 분야(점검, DB, 분석 및 예측 등)의 고도 기술을 집약하여 콘크리트 구조물을 관리할 필요가 있다. 이러한 배경에서 본 연구에서는 콘크리트 구조물의 효율적 관리 및 사용하기 위한 구조물 자 산관리 시스템에 대해서 제안하고자 한다.

For the development of flow duration curves for the management of 41 Total Maximum Daily Load (TMDL) units of the Nakdong River basin, first, an equation for estimating daily flow rates as well as the level of correlation (correlation and determination coefficients) was extrapolated through regression analysis of discrete (Ministry of Environment) and continuous (Ministry of Land, Infrastructure and Transportation) measurement data. The equation derived from the analysis was used to estimate daily flow rates in order to develop flow duration curves for each TMDL unit. By using the equation, the annual flow duration curves and flow curves, for the entire period and for each TMDL unit of the basin, were developed to be demonstrated in this research. Standard flow rates (abundant-, ordinary-, low- and drought flows) for major flow duration periods were calculated based on the annual flow duration curves. Then, the flow rates, based on percentile ranks of exceedance probabilities (5, 25, 50, 75, and 95%), were calculated according to the flow duration curves for the entire period and are suggested in this research. These results can be used for feasibility assessment of the set values of primary and secondary standard flow rates for each river system, which are derived from complicated models. In addition, they will also be useful for the process of implementing TMDL management, including evaluation of the target level of water purity based on load duration curves.

기후변화로 인해 강수의 불확실성이 증가하는 현 시점에서 효율적인 물 관리를 위한 계절예측 및 기상 예보의 활용은 필수적이다. 본 연구에서는 기상청에서 2014년 6월부터 시행하고 있는 범주형 확률장기예보를 Hit Rate, Reliability Diagram, Relative Operating Curve (ROC)의 평가지 표를 활용하여 예측력을 검증하였고, 추가적으로 확률예보를 활용하여 정량적인 예측 강수량을 생산하는 기법을 제안하였다. 확률장기예보의 예 측력 검증결과 최대 48%의 예측력을 갖는 것을 확인할 수 있었다. 확률예보를 활용하여 예측 강수량을 추정한 결과, 정량적으로 관측 자료와 유사 하게 모의되는 것을 확인할 수 있었으며 예측 적합도 평가결과 100%의 정확도를 가진 예보의 경우 최대 0.98, 실제 예보의 경우 최대 0.71의 상 관계수를 보였다. 본 연구에서 제안하는 확률예보를 활용한 예측 강수량 추출기법은 강수의 불확실성을 고려한 물 관리를 가능하게 해줄 것으로 판 단되며 효율적인 수자원 장기 이수계획 및 저수지 운영의 의사결정지원 등에 활용 가능할 것으로 기대된다.

최근 거푸집 작업과 철근 배근 공정을 생략하여 공정의 단순화를 통한 공기단축 합성 슬래브 시스템의 개발 연구가 진행 중이다. 이 연구에서는 구조용 데크플레이트를 활용하여 거푸집 및 인장철근의 배근을 대체하고 강섬유보강 콘크리트를 사용하여 온도철근의 역할을 대 체하는 단순슬래브 시스템의 장기거동을 평가하는 것이 목적이다. 구조용 데크플레이트를 활용하는 기존 합성슬래브 공법은 건조수축에 의한 균열 제어를 위해 용접 철망을 배근하는 것이 일반적이나, 이는 균열을 억제하는 데 효과적이지 못한 것으로 선행연구들에서 지적되었다. 본 연구에서는, 일반적인 건축물의 하중 조건으로 제작 된 연속 두 경간을 갖는 강섬유보강 데크플레이트 슬래브의 장기적인 균열 및 처짐 거동을 평가하도록 하였다. 실험 결과, 실험체의 비 내력부에서는 장기균열의 개수 및 폭이 현저하게 감소하는 것으로 나타나 강섬유보강 콘크리트의 건조수축과 균열 제어 성능이 우수한 것으로 평가되었으며,,처짐량도 강섬유보강 데크플레이트 슬래브가 우수한 것을 확인하였다. 다만, 부모 멘트가 작용되는 슬래브 연속단부에서는 사용하중 단계에서 균열폭을 제어하고 하중 제거 시 처짐을 회복하기 위한 디테일의 적용이 필요한 것으로 분석되었다.

We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.

본 연구는 유기농경지의 지속가능한 토양양분관리를 위해 유기농가의 자재의존도와 자 재에 의한 토양 특성변화를 알아보기 위하여 2016년 3월부터 6월까지 10년 이상 유기농을 실천한 토양의 화학적 특성과 함께 유기농가의 토양 관리를 위해 사용한 자재의 종류를 조 사하였다. 그 결과 유기농가에서는 토양 양분관리를 위해 주로 자가제조퇴․ 액비 및 시판자 재를 사용하고 있어 외부 투입자재의 사용빈도가 높음을 알 수 있었다. 그 중 57%는 가축 분뇨가 포함된 자재를 이용하여 토양관리를 하고 있었고 자재 성분분석 결과 가축분의 구 성 비율에 따라 자재의 성분함량이 다양하게 나타났다. 토양분석결과 10년 이상 유기농재 배를 한 지점의 양분함량은 대체로 높은 경향을 보였으며 농가에서 주로 사용하는 자재에 따라 토양 화학성이 차이가 나는 것을 알 수 있었다. 특히 가축분퇴비를 주로 사용하는 농 가는 교환성 칼슘과 칼륨이 과잉 존재하는 경향을 보였다. 또한 시판자재 분석결과 부숙유 기질비료는 가축분의 종류와 비율에 따라 성분함량 차이가 크게 나타났다. 이러한 외부투 입자재에 의존한 토양관리는 토양 내 양분 불균형을 야기할 수 있다. 토양 내 양분 불균형 은 작물 생산성을 악화시키고 환경오염의 우려가 있어 농가 및 연구현장에서 이를 개선하 기 위한 노력이 필요하다. 농가수준에서 토양 양분관리를 위해 사용하기 용이한 시판 부숙 유기질비료의 성분함량을 고려한 신중한 투입이 필요하며, 또한 이러한 유기농경지에서의 양분 불균형 해소를 위해 집적된 양분의 이용률을 증대시키는 방안에 대한 연구가 필요할 것으로 생각된다.

To determine the effect of air pollution reduction policies, the long-term trend of air pollutants should be analyzed. Kolmogorov-Zurbenko (KZ) filter is a low-pass filter, produced through repeated iterations of a moving average to separate each variable into its temporal components. The moving average for a KZ(m, p) filter is calculated by a filter with window length m and p iterations. The output of the first pass subsequently becomes the input for the next pass. Adjusting the window length and the number of iterations makes it possible to control the filtering of different scales of motion. To break down the daily mean PM10 into individual time components, we assume that the original time series comprises of a long-term trend, seasonal variation, and a short-term component. The short-term component is attributable to weather and short-term fluctuations in precursor emissions, while the seasonal component is a result of changes in the solar angle. The long-term trend results from changes in overall emissions, pollutant transport, climate, policy and/or economics. The long-term trend of the daily mean PM10 decreased sharply from 59.6 ug/m3 in 2002 to 44.6 ug/m3 in 2015. This suggests that there was a long-term downward trend since 2005. The difference between the unadjusted and meteorologically adjusted long-term PM10 is small. Therefore, we can conclude that PM10 is unaffected by the meteorological variables (total insolation, daily mean temperature, daily mean relative humidity, daily mean wind speed, and daily mean local atmospheric pressure) in Busan.

We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.

This study presented the change of quality characteristics of Doenjang with various salt concentrations (4, 8, 15, and 20%) during 12 months. The pHs of Doenjang during fermentation were gradually increased for 12 months, whereas the pHs of Doenjang with 4 and 8% salt increased rapidly. Titratable acidity of Doenjang with 4 and 8% salt was high at initial time, while Doenjang with 15 and 20% salt was high at the 9 and 12 months. The amino-type nitrogen content of Doenjang with 4 and 8% salt was increased and α-amylase activity of all Doenjang was decreased during whole fermentation period. The protease activity of Doenjang with 4 and 8% salt was higher than Doenjang with 15 and 20% salt until 7 months. Total aerobic bacteria number 8.0~9.1 log CFU/g for 12 months, which was steady during fermentation period. Doenjang with 8% salt showed the highest score in umami taste whereas the lowest score in bitterness, astringency, and sourness tastes between 5 and 12 months. In conclusion, Doenjang with 8% salt was a suitable concentration for low-salt fermented foods.

By analyzing the flexural capacity of shotcrete mixture with blast furnace slag and confirmed the suitability as subsea tunnel support of the long-term repeated soaked in chloride-ion slag shotcrete. As a result, the shotcrete mixture with slag is excellent evaluated in terms of flexural capacity compared with existing shotcrete.

The purpose of this experimental research is to evaluate the long-term resistance against sulfate attack of the alkali activated cementless concrete replacing the cement with ground granulated blast furnace slag. For this purpose, the cementless concrete specimens were made for water-binder ratios of 40%, 45%, and 50%, respectively and then this specimens were immersed in fresh water and 10% sodium sulfate solution for 28, 91, 182, and 365 days, respectively. To evaluate the long-term resistance to sulfate attack for the cementless concrete specimens, compressive strength ratio, mass change ratio, and length change ratio were measured according to the JSTM C 7401. It was observed from the test results that the resistance against sulfate attack of the cemetntless concrete was comparatively largely increased than that of OPC concrete irrespective of water-binder ratio.

본 연구는 유방암의 근접치료 시 수학적 모의피폭체를 이용하여 유방 및 인접장기의 선량을 평가하고자 하였다. 좌측 유방과 우측 유방을 선원으로 설정하여 192Ir과 103Pd 핵종에 대한 흡수선량을 분석하였다. 그 결과 선원 장기에 대한 선량은 192Ir이 103Pd에 비해 높은 흡수선량을 보였으며, 반대측 유방의 선량도 192Ir이 높게 나타났다. 또한 유방암의 근접치료 시 특히 유의해야 할 인접장기는 폐, 간, 심장, 반대측 유방으로 평 가되었다.

There are various method for evaluating the durability life of concrete structures due to salt damage . The best way is to perform a corrosion test for a rebar embedded in concrete specimen was exposure to marine environment. However, this method has the disadvantage that it takes a long period of time. Also, accelerated corrosion test which was complemented complements the time-consuming weakness is limited to apply because it could not reveal a correlation between long-term exposure test. Accordingly, the purpose of this study is to derive a correlation coefficient between cycle drying -wetting accelerated corrosion test and long-term exposure test. Corrosion initiation time was measured in four types of concrete samples, i.e., two samples mixed with fly ash(FA) and blast furnace slag(BS), and the other two samples having two water/cement ratio(W/C = 0.6, 0.35) without admixture(OPC 60 and OPC 35). The accelerated corrosion test was carried out by two case, i.e., one is a cyclic drying-wetting method(case 1), and the other is a artificial seawater ponding test method(case 2). Whether corrosion occurs, it was measures using half-cell potential method. The results indicated that case 1 is to accelerated the corrosion of rebar about 24~36% as compared with case 2, then the corrosion of rebar embedded in concrete occurred according to the order of OPC60, FA, BS, OPC35. Correlation coefficient between accelerated corrosion test and long-term exposure test, case 1 is 4.23 to 5.42, and case 2 is 6.54 to 7.82.

Recently, the pipeline system for waste transportation has been increasingly constructed as new solution for the waste collection and disposal system by constantly increasing domestic waste which issued as social problem. The pipeline system is constructed through long distance, so proper long-term monitoring system is necessary which available to detect the damage location for the effective maintenance. In this paper, the experimental study is carried out to evaluate the applicability of optical strain gauge sensor based on FBG for the long-term monitoring system. Three test parameters such as pressure leaking, blockage and deformation are considered as typical damages for real-scale pipeline test specimen. In order to measure flexural and volumetric strain and temperature, three FBG sensors are installed at each monitoring sections. From the test results, this study suggested effective methods of sensor installation and arrangement. Also the sensor spacing for the design of monitoring system using FBG sensor is derived by the correlation of distances from deformation between sensor responses.

Floor damping materials used in floating floor system to diminish the floor noise have been made with low density and dynamic stiffness. Owing to this low density and dynamic stiffness, the deflection in these materials under long-term loading and cracking of the floor finishing mortar in the floating floor system may occur. This paper presents the results of long-term loading effects on the deflection of different types of floor damping materials. The experimental program involved the long-term loading tests for 490 days loading period on sixteen specimens. Specimens were classified as DM1(Damping Materials) to DM8, depending upon the four main parameters; types, bottom shapes and densities of floor damping materials and amount of loading. Results indicated that the long-term deflection of all specimens of damping materials remained unchanged after 200 days at all loading amounts, except the specimens made up of Polystrene, in which long-term deflection remained unchanged after 160 days at 250 N load and 100 days 500 N load. In this paper, two types of correlation expressions were shown in the deflection range prior to the range where deflection remained constant; two analyses by ISO 20392 and linear regression. In comparison of two analyses and experimental results on the difference of deflection of 16 specimens, the difference of deflection was below 0.4 mm in those analyses in case of that total deflection was below 10 mm. Restrictively, it was judged that the analysis for the deflection of specimens made up of Polystrene is more appropriate using ISO 20392.

Background : Aralia cordata and Polygonum multiflorum GAP cultivation requires a stable drying and storage settings after harvesting. therefore, this experiment was performed in order to effectively manage the physical, chemical and biological hazards. Methods and Results : Test materials were used biennial Aralia cordata, Polygonum multiflorum harvested from the medicinal testing ground. The drying temperatures were treated with 40, 50, 6 0℃ and natural drying. Storage containers were stored in plastic boxes, styrofoam boxes and kraft paper containers, examined the color and quality changes for eight months. Aralia cordata and Polygonum multiflorum drying temperature is dry it took natural drying 720 hours, 40℃ hot air drying 180 hours, 50℃ hot air drying 168 hours and 60℃ hot air drying 108 hours. However, the difference chromaticity of the Lab value corresponding to the temperature does not appear, it was good to dry in a short time at 60℃. Aralia cordata and Polygonum multiflorum stored in a styrofoam box storage method but can be stored at room temperature for up to four months, began to decay caused by moisture content it continues to increase. In plastic box in case of Aralia cordata and kraft vessel in case of Polygonum multiflorum can be stored for eight months in room temperature without decay. Styrofoam boxes stored at 5℃ cold storage were higher water absorption such as room temperature, but decay did not occur. Plastic box and styrofoam box were a tendency such as room temperature. Conclusion : Aralia cordata and Polygonum multiflorum are thought that the color change is not large depending on the drying temperature the lower the water content. Styrofoam storage box, the air permeability is higher than plastic boxes and containers Kraft vessel, decay occurs expected increase.

The purpose of this study was to investigate deformation and reduction of initial clamping force in slip critical type connection under fatigue loading. And, the parameters of this study were the different clamping force and friction coefficient of surface of plate. As a result, the clamping force of all specimens were generally decreased in comparison with initial values under fatigue loading.

Accelerated alkali resistance test were conducted for pre-heated GFRP Rebar. The GFRP rebar specimens were heated to temperatures of 60℃, 120℃, 200℃ and 300℃ and then immerged in alkali solution for 30days. According to ACI 440.3R-12, tensile properties were measured.

This study focused on whether the large-scale expansion joints of the Diamond Bridge, a suspension bridge, is being appropriately and efficiently utilized during maintenance period. In this study, a linear regression model was developed by analyzing long-term monitoring data from the bridge, considering the bridge design standards in Korea and building-related literatures. Then, the reliability of the model was verified through a theoretical review on the relationship between temperature change and expansion joint displacement. The expansion joint displacements of the bridge showed a regular time series graph with temperature change. A linear regression analysis indicated that the slope of the graph was very similar to the displacement of steel due to linear expansion coefficient, with a high determination coefficient (R2=0.979), meaning that the actual behavior of the bridge conforms to the theory. Considering the expansion joint specification of the bridge and existing external loads, actual expansion joint displacement was only 8.5 percent of its specification, so the specification can be adjusted in order that actual expansion joint displacement can be up to 21.6 percent of its specification. In this case, expansion joint cost can be reduced as much as 78.4 percent of its original cost.

In this study, the behavior of the existing tunnel was measured by automation system to analyze the characteristics of lining longitudinal cracks. The characteristic of the infusion material which it is applicable to crack repairing was considered by grasping the overall behavior including the temperature and the crack width change, and etc., From this, the reasonable repair period for the complement efficiency enhancement was trying to be determined.