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        검색결과 67

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.
        4,800원
        2.
        2023.05 구독 인증기관·개인회원 무료
        Decommissioning plan of nuclear facilities require the radiological characterizations and the establishment of a decommissioning process that can ensure the safety and efficiency of the decommissioning workers. By utilizing the rapidly developed ICT technology, we have developed a technology that can acquire, analyze, and deliver information from the decommissioning work area to ensure the safety of decommissioning workers, optimize the decommissioning process, and actively respond to various decommissioning situations. The established a surveillance system that monitors nuclide inventory and radiation dose distribution at dismantling work area in real time and wireless transmits data for evaluation. Developed an evaluation program based on an evaluation model for optimizing the dismantling process by linking real-time measurement information. We developed a technology that can detect the location of dismantling workers in real time using stereovision cameras and artificial intelligence technology. The developed technology can be used for safety evaluation of dismantling workers and process optimization evaluation by linking the radionuclides inventory and dose distribution in dismantling work space of decommissioning nuclear power plant in the future.
        3.
        2023.05 구독 인증기관·개인회원 무료
        Timely detection of nuclear activity is important for the management and supervision of nuclear materials, and inspections on North Korea as a method of safety measures for this monitoring system seem to be a not far future in the rapidly changing North Korea relationship. However, a simpler and more reliable monitoring device is required since the inspection period is limited and the possibility of revisiting is unclear. The seal is a simple but easily used security device for monitoring forgery and falsification in the IAEA. IAEA presents matters related to 1) project engineering, 2) remote monitoring, and 3) seal development as the three major tasks of the Department of safeguards and Division of Technical Support. The importance of development, modernization, and application of new seal devices is emphasized, and advanced sealing and identification system development is in progress at many research institutes such as JRC, ISCN, and JAEA. Since the existing seal devices used by IAEA and KINAC can only be confirmed through on-site inspections for damage, it is difficult to respond immediately in the event of similar situations such as theft of nuclear materials and loss of continuity of knowledge. Unlike facilities that comply with the requirements for safety measures, such as domestic nuclear facilities, in the case of facilities subject to denuclearization, it is very likely that various hazardous environments will exist that make it difficult to apply safety measures. Hence, a real-time seal device has developed through prior research due to the high possibility of situations in which Continuity of Knowledge (COK) is not maintained, such as damage, malfunction, and power loss of sealing and monitoring equipment. Through previous studies, the real-time seal device was loaded with server-based operating software and improved its performance by utilizing feedback from real users (KINAC) after use. In this study, the effectiveness of the previously developed sealing system was verified through performance evaluation, and the authentication of the equipment was secured through environmental tests.
        4.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is essential to determine a proper earthquake time history as a seismic load in a seismic design for a critical structure. In the code, a seismic load should satisfy a design response spectrum and include the characteristic of a target fault. The characteristic of a fault can be represented by a definition of a type of possible earthquake time history shape that occurred in a target fault. In this paper, the pseudo-basis function is proposed to be used to construct a specific type of earthquake, including the characteristic of a target fault. The pseudo-basis function is derived from analyzing the earthquake time history of specific fault harmonic wavelet transform. To show the feasibility of this method, the proposed method was applied to the faults causing the Gyeong-Ju ML5.8 and Pohang ML5.3 earthquakes.
        4,000원
        6.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluates the ammonia (NH3) reduction effect of Bio-curtains (hereinafter referred to as curtains) utilized for odor control in pig farms based on the distance outside the curtain and the spraying condition. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around a ventilation fan (630 mm) on the side wall of a pig barn where 48 finishing pigs were reared. The real-time NH3 concentration was measured by using a photoacoustic spectrometer. In the first part of this study, the NH3 measurement position for each side of the curtain was selected based on the lowest standard deviation among 4 to 8 initial sampling points on the surface of the curtain and utilized for both experiments of distance and spraying. In the experiment concerning the distance outside the curtain, ammonia concentration decreased by 17.45% at 2m compared to the distance at 5 cm and by 6.94% at 4m compared to 2m on average. In contrast, the NH3 reduction rate for each distance compared to the ventilation fan was the lowest at the 100% operating rate in which the exhausted NH3 concentration from the ventilation fan was low. At this time, the spraying mist on the inside of the curtain increased the NH3 reduction rate by 4.98 to 10.36% compared to the non-spraying condition. Consequently, the NH3 be reduced as distance outside the curtain increases due to the diffusion effect caused by the surrounding wind and the spraying mist on the inside curtain on the dissolution of NH3.
        4,000원
        7.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Recently, increasing number of local governments are introducing on-demand public transportation service in real time to improve the management efficiency of public transportation. In preparation for the autonomous driving era, the “autonomous public transportation mobility on-demand service in real time” is being developed in the public transportation sector to introduce on-demand public transportation. For this service to become the public transportation of the future, it must receive publicity. Therefore, in this study, indicators were selected to evaluate the publicity of the autonomous public transportation mobility on-demand service in real time, and a survey was conducted among the general public to examine the validity of the indicators. METHODS : To secure the publicity of on-demand public transportation in real time, the goal of the service was first set. Second, the keywords of the service were analyzed to define the publicity requirements of this service. Based on the analyzed keywords and definition of publicity, service indicator types were classified, and the indicators were defined by type. A user satisfaction survey was conducted on the final selected indicators to improve the degree of completion of indicator development. The user survey was conducted by presenting selected publicity indicators to respondents responding on a five-point scale to determine whether each indicator could satisfactorily evaluate publicity. RESULTS : When examining various previous research cases and the contents required for autonomous public transportation mobility on-demand service in real time, the required items of publicity indicators were found to be “safety” in terms of “autonomous driving” and “convenience” in terms of “demand response.” Publicity indicators were developed according to these three items. Thirty-one indicators were developed, and a satisfaction survey was conducted on the general public for each indicator. In the survey, most of the indicators scored 3.5 points or higher, indicating that the indicators were generally well defined. Users gave the highest score to “fairness” among the three items, and “reasonable fairness” was found to be a necessary item as a publicity indicator. CONCLUSIONS : In this study, evaluation indicators were selected to secure the publicity of autonomous public transportation mobility on-demand service in real time, and a satisfaction survey was conducted for each indicator. Most of the indicators showed a score of 3.5 or higher, indicating that they were generally well defined. However, this study has a limitation in that it surveys the general population. In future, experts should be included in the survey to increase the degree of completeness of the public indicators.
        4,000원
        8.
        2022.05 구독 인증기관·개인회원 무료
        HIC refers to a radwaste packaging container that can maintain integrity for more than 300 years in the general underground environment and disposal conditions in Korea. For HIC, the integrity of containers is verified according to the HIC regulation guideline for LLW and ILW disposal. Existing material tests include mechanical stability, permeability resistance, corrosion properties, chemical durability and biological resistance. In this study, a chemical durability test was conducted to prove the suitability of the HIC material by measuring the degree of chemical influence other than corrosion from the disposal environment. The chemical resistance evaluation method was used to simulate the disposal environment in the underground repository, and the amount of change in the physical properties of the degraded polymer concrete specimens according to the test time was confirmed. The technical standards considered leaching of material components, sulfation attack, acid attack, alkali, carbonate, and salt crystallization. The compressive strength and weight change of the specimens with time were checked by immersing them in a chemical solution that could leak major hazardous substances and wastes in the groundwater of the repository for several months. In addition, in order to evaluate the integrity in condition severe than the disposal environment, a flow was applied to a chemical solution having a concentration twice that of the basic chemical resistance test conditions, and the test period was extended twice to accelerate the deterioration of the specimen.
        10.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study was to evaluate the newly developed Guss mastic asphalt mixtures, called EQ-mastic asphalt mixtures, which contain melted additives for decreasing cooking time. METHODS : A series of experiments were performed to investigate the effectiveness of the melted additives in EQ-mastic asphalt mixtures. Both the existing Guss mastic asphalt mixture and the EQ-mastic asphalt mixture were produced with the same amounts of asphalt binders, aggregates, and fillers, but the existing Guss mastic asphalt mixture contained 3% Trinidad lake asphalt (TLA). The EQ-mastic asphalt mixture contained 3% of additives, including TLA and polyolefin. The physical material performances of both mastic asphalt mixtures were obtained by conducting the Luer fluidity test, penetration test, dynamic stability test, and low-temperature bending test. The results of the tests for the existing Guss mastic and EQ-mastic asphalt mixtures were compared. RESULTS : The fluidity, penetration, dynamic stability, and low-temperature bending strains of both the existing Guss mastic and EQmastic asphalt mixtures all satisfied the standard values provided in the production and construction guides of the Guss mastic asphalt pavement. CONCLUSIONS : When melted additives containing polyolefin are used in the production of Guss mastic asphalt mixtures, the cooking time decreases, so that the corresponding energy consumption and asphalt fume amount can be reduced. Therefore, an EQ-mastic asphalt mixture is proposed for use as an eco-friendly pavement material.
        4,000원
        11.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 동맥스핀라벨링을 이용하는 비 조영증강 기법인 4D TRANCE으로 동정맥기형 환자를 진단함에 있어 기존에 사용하고 있는 4D TRAK과 조영증강 3D TOF으로 얻는 진단적 정보의 재현성과 유용성을 알아보고자 하였다. 연구방법 은 동정맥기형 추적검사를 하는 환자 14명을 대상(남자 4명, 여자 10명)으로 하여 뇌혈관 영상을 각각 4D TRANCE, 4D TRAK, 조영증강 3D TOF를 순서로 획득하였다. 영상의학과 전문의 2명이 3 영상의 진단적 평가와 영양동맥(feeding artery, FA)과 배출정맥(draining vein, DV)을 비교 평가하였고, 동일한 부위의 병소(nidus)와 내경동맥에 대한 대조도 잡음비를 비교 분석하였다. 정성평가는 4D TRANCE는 진단적 정확도 3.93(3.89~4.04), FA 3.75(3.55~3.95), DV 1.96(1.77~2.16) 으로 모든 구간에서 4D TRAK과 비교하여 통계적으로 유의하였으나(p<0.001), 유일하게 DV에서 유의하지 않았다. 정량 분석에서는 4D TRANCE와 3D TOF의 대조도 잡음비에 따른 독립표본 T검정 결과, 조영증강되는 병소에서는 4D TRANCE가 3D TOF에 비해 15.50의 차이로 높았으며, 통계적으로 유의하였다. 본 연구는 동정맥기형 추적검사에 대해 4D TRANCE는 4D TRAK보다 다소 저하된 영상품질을 보여주었으나, 3D TOF와 비교했을 때 혈관 해부학 및 혈류역학 정보를 제공하기 때문에 더 신뢰할 수 있는 정보를 제공하여 임상 영상 평가에 유용하게 사용할 수 있다.
        4,000원
        12.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This paper presents the development and evaluation of the smart hardware-in-the-loop systems (SMART-HILS) that evaluate traffic signal operations of a new real-time traffic signal control system called SMART SIGNAL at the traffic management center (TMC) level. METHODS: The layouts of the hardware and software components of the SMART-HILS were introduced in this study and its performance was tested using real-time traffic signal operation algorithms embedded in the SMART SIGNAL control server by utilizing the VISSIM simulation model. In this study, the SMART-HILS management software was developed using .NET programming language. Fewer random seed numbers were used for the test scenarios by conducting statistical tests to address the shortcomings of a longer time due to the adoption of the simulation time as the real-time by the TMC server. RESULTS : It was determined that SMART-HILS can communicate with TMC and VISSIM for both upload and download directions within acceptable time constraints and evaluate new design algorithms for traffic signal timing. CONCLUSIONS : In practice, traffic engineers can utilize SMART-HILS for testing the traffic signal operation alternatives before their selection and implementation. This application could increase the productivity of traffic signal operation.
        4,000원
        13.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내에서 육성된 중생종 동양배 ‘신화’의 과실 생장 및 성숙기간 중의 품질요인을 평가하고 수확시기별 1-methylcyclopropene (1-MCP) 훈증처리 효과가 25℃ 유통 중 과실품질 및 생리장해 발생에 미치는 영향을 구명하고자 실시하였다. 만개 후 125일부터 153일까지 1주일 간격으로 품질요인을 조사한 결과, 경도는 경시적으로 저하되어 만개 후 146일인 9월 6일에 29.9N이었고, 만개 후 153일에는 21.5N으로 급격히 경도가 저하되었다. 과실성숙의 진행과 더불어 알콜불용성물질 함량은 지속적으로 낮아짐과 동시에 가용성고형물함량이 증가하여 만개 후 146일에 각각 8.13mg·g FW-1 및 11.2oBrix 로 조사되었다. 성숙기간 중 과당이 우점하고 있었고, 과실성숙도가 높아질수록 자당의 비율이 유의하게 증가하는 경향이었는데 만개 후 153일에 수확한 과실에서도 자당이 과당을 넘어서 우점하지는 않았다. 수확 시기별 1.0μL·L-1 1-MCP 훈증 처리가 유통 중 무처리구 과실에 비해 높은 경도를 유지하였다. 수확시기 간에는 만개 후 146일에 수확한 과실에 대한 1-MCP 처리가 만개 후 153일 수확 과실에 비하여 유통 중 경도 유지 효과가 높았다. 바람들이 장해의 발생은 만개 후 146일에 수확한 과실은 유 통 28일 이후 증가하기 시작하였고, 만개 후 153일 수확 과실의 경우에는 유통 21일부터 급증하였는데 1-MCP 처리는 ‘신화’ 배의 생리장해 발생을 경감하지 못하였다.
        4,000원
        14.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 2012년 1월부터 2019년 1월까지 과천경마공원에서 경주한 더러브렛, 6,762두의 주파기록, 총 82,796개를 이용하여 동기군의 구성을 조사하기 위하여 수행되었다. 모든 경주거리에서 우승마의 주 파기록이 1초 감소하면 해당 경주의 평균 주파기록은 0.89초에서 0.99초 감소하였다. 주파기록에 대한 동기군의 효과는 총변이의 약 41%를 차지하였으며, 참가경주의 효과는 일괄적으로 모든 경주거리에서 가장 크게 나타났다. 동기군을 포함한 모형(Ⅰ)과 우승마 기록을 포함한 모형(Ⅱ)에서 추정된 주파기록에 대한 유전분산은 각각 0.4760과 0.4148, 유전력과 반복력은 각각 0.26, 0.47과 0.22, 0.40이었다. 모형 Ⅱ에서 추정된 유전분산과 유전력은 모형 1에 비하여 각각 13%와 15% 감소하는 것으로 나타났으며, 우승마의 주파기록을 환경효과로 모형에 포함하는 것보다는 동기군을 포함하는 것이 주파기록을 량하는데 있어서 더 유리할 것으로 판단되었다.
        4,000원
        15.
        2018.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Angiotensin receptor blockers, such as telmisartan, are considered effective in the treatment of hypertension and proteinuria due to chronic kidney disease (CKD) in cats. It selectively blocks the AT1 receptor and does not affect the AT2 receptor, thus effectively blocking the activity of the renin angiotensin aldosterone system. This study aims to compare over time the changes in various indicators, including systemic hypertension and proteinuria, before and after the administration of telmisartan in cats with CKD. Decrease in blood pressure (BP) (p<0.001) and urine protein to creatinine (UP/C) ratio (p<0.001) were found to be statistically significant over time after the administration of telmisartan. BP and the UP/C ratio were 160 ± 22.2 and 0.50 ± 0.647 before telmisartan administration (Day 0), 150 ± 21.0 and 0.27 ± 0.487 on the 30th day (Day 30), 150 ± 17.0 and 0.25 ± 0.376 on the 60th day (Day 60), and 140 ± 17.8 and 0.15 ± 0.233 on the 90th day (Day 90) after administration, respectively. BP and UP/C were statistically significantly lower in cats with CKD over time at each time point from Day 0 to Day 90 at 30 day intervals. Especially after 90 days of telmisartan administration, the improvement of BP and UP/C were estimated to be about 20 mmHg and 0.35, respectively. In conclusion, the oral administration of telmisartan to cats with CKD is effective in improving BP and proteinuria, which has a positive effect on long-term survival in cats with CKD.
        4,000원
        17.
        2018.05 구독 인증기관·개인회원 무료
        Three CNN (Convolutional Neural Network) models of GoogLeNet, VGGNet, and Alexnet were evaluated to select the best deep learning based image analysis mothod that can detect pavement distresses of pothole, spalling, and punchout on expressway. Education data was obtained using pavement surface images of 11,056km length taken by Gopro camera equipped with an expressway patrol car. Also, deep learning framework of Caffe developed by Berkeley Vision and Learning Center was evaluated to use the three CNN models with other frameworks of Tensorflow developed by Google, and CNTK developed by Microsoft. After determing the optimal CNN model applicable for the distress detection, the analyzed images and corresponding GPS locations, distress sizes (greater than distress length of 150mm), required repair material quantities are trasmitted to local maintenance office using LTE wireless communication system through ICT center in Korea Expressway Corporation. It was found out that the GoogLeNet, AlexNet, and VGG-16 models coupled with the Caffe framework can detect pavement distresses by accuracy of 93%, 86%, and 72%, respectively. In addition to four distress image groups of cracking, spalling, pothole, and punchout, 22 different image groups of lane marking, grooving, patching area, joint, and so on were finally classified to improve the distress detection rate.
        18.
        2018.04 구독 인증기관·개인회원 무료
        A pultruded fiber reinforced polymer plastic (PFRP) structural is one of the most widely used composite member in construction. In generally, PFRP members is composed of plate elements so that it needs to evaluate stability problems when they are used by construction members. On the other hand, creep effect may be occurred in PFRP members under sustained load. Primary to experiment for PFRP creep, previous works are studied. In the previous work related to buckling of PFRP member, it can be calculated buckling strength of PFRP members when it is known that material property of longitudinal and transverse direction of PFRP members. The researches for creep behavior of PFRP has been conducted and time-dependent degradation elastic moduls can be predicted by the empirical equation. In this study, it will be conducted creep test for PFRP and time-dependent stress-strain relationship will be plotted. It is expected that long-term buckling behavior of PFRP is evaluated by theoretical and numerical method such as finite element method.
        19.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 기구등에 오염된 E. coli와 S. aureus를 제어 하기 위해 이산화염소의 농도별 접촉시간에 따른 살균소 독력을 평가하여 살균예측모델을 개발하였다. E. coli의 경우 초기균수가 9.13 log CFU/mL이었고, 청정조건에서 5 ppm으로 1분, 3분, 5분 처리한 결과 각각 0.04, 0.07, 0.10 log CFU/mL의 감소값을 나타내었다. 20 ppm을 처리한 결 과 각각 0.74, 0.79, 0.84 log CFU/mL의 감소값을 나타내었다. 또한 CCD에 의한 최대농도 35 ppm으로 처리한 결과 각각 2.49, 2.70, 3.65 log CFU/mL의 감소값을 나타내었다. S. aureus의 경우 초기균수가 8.70 log CFU/mL이었고, 청정조건에서 5 ppm으로 1분, 3분, 5분 처리한 결과 각각 0.14, 0.28, 0.36 log CFU/mL의 감소값을 나타내었다. 20 ppm을 처리한 결과 각각 0.66, 0.79, 0.90 log CFU/mL의 감소값을 나타내었다. 또한 CCD에 의한 최대농도 35 ppm 으로 처리한 결과 각각 4.59, 5.25, 5.81 log CFU/mL의 감소값을 나타내었다. 따라서 이산화염소의 살균소독력 평 가결과는 E. coli와 S. aureus에 대하여 식품의약품안전처 살균소독력 기준에 모두 만족하는 것으로 나타났다. 살균 예측모델의 경우, R2값이 모두 0.98 이상으로 두 균주에 대해 모두 높은 적합성을 보였다. 본 연구에서 개발된 이산화염소의 살균예측모델을 식품산업 적용을 위한 기초자 료로 활용함으로써 E. coli와 S. aureus를 적절한 농도와 접촉시간으로 제어할 수 있을 것으로 사료된다.
        4,000원
        20.
        2017.10 구독 인증기관·개인회원 무료
        The Joint Load Transfer (LTE) is important for both design and evaluation of concrete pavements. Numerous researches have been published to determine different factors that affect the load transfer efficiency through Finite Element Method (FEM) and field measurements. Most of these researches are using static analysis. Previous study pointed out the weakness of the assumption of this analysis and successfully differentiate the dynamic stress-based LTE with static stress-based LTE through FEM. Usually deflection based LTE(w) is being evaluated in the field through Heavy Weight Deflectometer (HWD). This test is a dynamic test which typically uses peak displacement and assumed to be static displacement when similar amount of static loading is applied. The calculation of LTE(w) in the field involves the ratio of the peak displacement of unloaded to loaded slab. Using this LTE(w) calculation, there were instances that high values were obtained from spalled joints and joints with wider opening. This study attempts to provide a better characterization of the condition of the joint. A time-based LTE(t) using the time delay were investigated and correlated with the current LTE(w) using a 24 hour measurement of deflection from asphalt and concrete pavement, with a 3-hour interval done in Gimpo International Airport. Wider values of LTE(t) were obtained while the deflection-based LTE(w) shows almost similar values. The time-based LTE(t) shows better relationship with the physical condition of the joint than LTE(w). It shows that LTE(t) can characterized the condition of the joint. This result will be used for further study to improve the measurement of load transfer efficiency of concrete pavement joints
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