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        검색결과 529

        41.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the demand for ready-to-eat foods continues to grow, concerns about the sodium in processed foods are also growing. In this study, a survey was conducted on the perception of low-sodium products and diffusion plans according to the type of employee (manufacturer, retailer, distributor). Of the 191 responses collected, 189 valid responses (98.9%) were analyzed. The results showed that the employees were aware of the health contribution of a low-sodium diet, labeling for low-sodium, and the promotion of low-sodium food to increase its consumption. Furthermore, retailers recognized the positive contribution of low-sodium products in terms of Environmental, Social, and Governance (ESG) management. The use of sodium substitutes was preferred as the best way to reduce sodium in ready-to-eat foods. With regard to sodium reduction in readyto- eat foods, we found that the technical factors involved were clustered by the type of business. Specifically, distributors showed a similar performance but had a lower perception of importance than retailers. Manufacturers had a lower perception of both importance and performance. In this study, we collected perceptions from employees who were working at food companies, which differed from previous research. We sought to examine the differences in the perception of sodium reduction and consumption of ready-to-eat foods across various types of employment. Furthermore, we provided specific approaches to reduce perception gaps and enhance understanding among employees.
        4,600원
        42.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the case of a school building, even though it is a regular structure in terms of plan shape, if the masonry infill wall acts as a lateral load resisting element, it can be determined as a torsionally irregular building. As a result, the strength and ductility of the structure are reduced, which may cause additional earthquake damage to the structure. Therefore, in this study, a structure similar to a school building with torsional irregularity was selected as an example structure and the damping performance of the PC-BRB was analyzed by adjusting the eccentricity according to the amount of masonry infilled wall. As a result of nonlinear dynamic analysis after seismic reinforcement, the torsional irregularity of each floor was reduced compared to before reinforcement, and the beams and column members of the collapse level satisfied the performance level due to the reduction of shear force and the reinforcement of stiffness. The energy dissipation of PC-BRB was similar in the REC-10 ~ REC-20 analytical models with an eccentricity of 20% or less. REC-25 with an eccentricity of 25% was the largest, and it is judged that it is effective to combine and apply PC-BRB when it has an eccentricity of 25% or more to control the torsional behavior.
        4,000원
        43.
        2023.05 구독 인증기관·개인회원 무료
        Bentonite, a material mainly used in buffer and backfill of the engineering barrier system (EBS) that makes up the deep geological repository, is a porous material, thus porewater could be contained in it. The porewater components will be changed through ‘water exchange’ with groundwater as time passes after emplacement of subsystems containing bentonite in the repository. ‘Water exchange’ is a phenomenon in which porewater and groundwater components are exchanged in the process of groundwater inflow into bentonite, which affects swelling property and radionuclide sorption of bentonite. Therefore, it is necessary to assess conformity with the performance target and safety function for bentonite. Accordingly, we reviewed how to handle the ‘water exchange’ phenomenon in the performance assessment conducted as part of the operating license application for the deep geological repository in Finland, and suggested studies and/or data required for the performance assessment of the domestic disposal facility on the basis of the results. In the previous assessment in Finland, after dividing the disposal site into a number of areas, reference and bounding groundwaters were defined considering various parameters by depth and climate change (i.e. phase). Subsequently, after defining reference and bounding porewaters in consideration of water exchange with porewater for each groundwater type, the swelling and radionuclides sorption of bentonite were assessed through analyzing components of the reference porewater. From the Finnish case, it is confirmed that the following are important from the perspective of water exchange: (a) definition of reference porewater, and (b) variations in cation concentration and cation exchange capacity (CEC) in porewater. For applying items above to the domestic disposal facility, the site-specific parameters should be reflected for the following: structure of the bedrock, groundwater composition, and initial components of bentonite selected. In addition, studies on the following should be required for identifying properties of the domestic disposal site: (1) variations in groundwater composition by subsurface depth, (2) variations in groundwater properties by time frame, and (3) investigation on the bedrock structure, and (4) survey on initial composition of porewater in selected bentonite The results of this study are presumed to be directly applied to the design and performance assessment for buffer and backfill materials, which are important components that make up the domestic disposal facility, given the site-specific data.
        44.
        2023.05 구독 인증기관·개인회원 무료
        Korea Atomic Energy Research Institute is developing a radionuclide management processes as a conditioning technology to reduce the burden of spent fuel disposal. The radionuclide management process refers to a process managing radionuclides with similar properties by introducing various technology options that can separate and recover radionuclides from spent fuels. In particular, it is a process aimed at increasing disposal efficiency by managing high-heat, high-mobility, and high-toxic radionuclides that can greatly affect the performance of the disposal system. Since the radionuclide management process seeks to consider various technology options for each unit process, it may have several process flows rather than have a single process flow. Describing the various process flows as a single flow network model is called the superstructure model. In this study, we intend to develop a superstructure model for the radionuclide management process and use it as a model to select the optimal process flow. To find the optimal process flow, an objective function must be defined, and at the fuel cycle system level multiple objectives such as effectiveness (disposal area), safety (explosure dose), and economics (cost) can be considered. Before performing the system-level optimization, it is necessary to select candidates of process flow in consideration of waste properties and process efficiency at the process level. In this study, a sensitivity analysis is conducted to analyze changes in waste properties such as decay heat and radioactivity when the separation ratio varies due to the performance change for each unit process of the radionuclide management process. Through this analysis, it is possible to derive a performance range that can have waste properties suitable for following waste treatment, especially waste form manufacturing. It is also possible to analyze the effect of waste properties that vary according to the performance change on waste storage and management approaches.
        45.
        2023.05 구독 인증기관·개인회원 무료
        In the wake of the Fukushima NPP accident, research on the safety evaluation of spent fuel storage facilities for natural disasters such as earthquakes and tsunamis has been continuously conducted, but research on the protection integrity of spent fuel storage facilities is insufficient in terms of physical protection. In this study, accident scenarios that may occur structurally and thermally for spent fuel storage facilities were investigated and safety assessment cases for such scenarios were analyzed. Major domestic and international institutions and research institutes such as IAEA, NEA, and NRC provide 13 accident scenario types for Spent Fuel Pool, including loss-of-coolant accidents, aircraft collisions, fires, earthquakes. And 10 accident scenario types for Dry Storage Cask System, including transportation cask drop accidents, aircraft collisions, earthquakes. In the case of Spent Fuel Pool, the impact of the cooling function loss accident scenario was mainly evaluated through empirical experiments, and simulations were performed on the dropping of spent nuclear fuel assembly using simulation codes such as ABAQUS. For Dry Storage Cask System, accident scenarios involving structural behavior, such as degradation and fracture, and experimental and structural accident analyses were performed for storage cask drop and aircraft collision accidents. To evaluate the safety of storage container drop accidents, an empirical test on the container was conducted and the simulation was conducted using the limited element analysis software. Among the accident scenarios for spent fuel storage facilities, aircraft and missile collisions, fires, and explosions are representative accidents that can be caused by malicious external threats. In terms of physical protection, it is necessary to analyze various accident scenarios that may occur due to malicious external threats. Additionally, through the analysis of design basis threats and the protection level of nuclear facilities, it is necessary to derive the probability of aircraft and missile collision and the threat success probability of fire and explosion, and to perform protection integrity evaluation studies, such as for the walls and structures, for spent fuel storage facilities considering safety evaluation methods when a terrorist attack occurs with the derived probability.
        47.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 마찰모델에 따라 다른 마찰진자시스템(FPS)이 적용된 교량의 성능을 비교・분석하기 위해 구조해석을 수행하였다. 마찰해석모델 별 성능을 분석하기 위해 PVDF/MgO 마찰재의 마찰계수를 활용하여 쿨롱 마찰모델과 속도 의존 마찰모델을 구축했다. 쿨롱 마찰모델은 마찰속도와 관계없이 단일 마찰계수를 사용하며, 속도 의존 마찰모델은 마찰속도에 따른 마찰계수의 변화를 반영하 는 마찰모델이다. 지진해석으로 비선형 시간 이력 해석과 지진 취약도 해석을 수행하여 구조물의 응답을 확인하였다. 마찰모델에 따 른 바닥판과 교각의 지진 응답을 활용해 면진된 교량의 성능을 분석하였으며, 면진된 교량의 성능을 효과적으로 평가할 수 있는 마찰 모델을 분석했다.
        4,000원
        50.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Various linear system solvers with multi-physics analysis schemes are compared focusing on the near-field region considering thermal-hydraulic-chemical (THC) coupled multi-physics phenomena. APro, developed at KAERI for total system performance assessment (TSPA), performs a finite element analysis with COMSOL, for which the various combinations of linear system solvers and multi-physics analysis schemes should to be compared. The KBS-3 type disposal system proposed by Sweden is set as the target system and the near-field region, which accounts for most of the computational burden is considered. For comparison of numerical analysis methods, the computing time and memory requirement are the main concerns and thus the simulation time is set up to one year. With a single deposition hole problem, PARDISO and GMRESSSOR are selected as representative direct and iterative solvers respectively. The performance of representative linear system solvers is then examined through a problem with an increasing number of deposition holes and the GMRES-SSOR solver with a segregated scheme shows the best performance with respect to the computing time and memory requirement. The results of the comparative analysis are expected to provide a good guideline to choose better numerical analysis methods for TSPA.
        4,000원
        51.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to compare and analyze the flame retardant performance of Japanese cypress(Chamaecyparis obtusa) plywood, commonly used in indoor decoration, furniture, and tableware, by treating it with three different fire retardants with different primary ingredients. The experiment was conducted in compliance with Article 31, Paragraph 2 of the Enforcement Decree of the Fire Facilities Installation and Management Act and Articles 4 and 7-2 of the Flame Retardant Performance Standards. After flame time, after glow time, char length, and char area were measured. As a result, first, after flame time was measured at 0 seconds regardless of whether the flame retardant treatment was applied. Second, after glow time was relatively long, measuring 22.7 seconds without treatment, which is likely due to the weak fire resistance and high concentration of carbon monoxide generated by the chemical characteristics of the Japanese cypress itself. Third, it was confirmed that the effects of the primary ingredient, phosphorus, in the flame retardant treatment varied depending on the technological development of the manufacturers of the same species of Japanese cypress plywood. In the future, it is expected that the results of this study will provide fundamental data to select flame retardant treatments that show high flame retardant performance according to the botanical characteristics of the wood.
        4,000원
        52.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        지식기반사회에서 산학협력의 중요성이 지속적으로 높아짐에 따라 정부는 산학협력 관련 다양한 사업을 추진하고 있다. 하지만 정부의 많은 지원에도 불구하고 만족스러운 성과를 거두지 못하고 있어 산학협력 성과를 확산하기 위한 실증적 성과분석의 필요성이 커지고 있다. 본 연구에서는 DEA를 활용하여 LINC+ 참여 대학의 산학협력 성과를 분석하였다. CCR 모형과 BCC 모형을 활용하여 효율성 분석을 수행하였으며, 규모효율성 분석을 통해 규모수익과 비효율 원인을 파악하였다. 또한 비효율적으로 운영되는 대학에 대하여 효율성 개선목표를 제시하였다. 분석 결과 대학이 위치한 지역에 따라 LINC+ 성과의 차이가 있으며, 대학별 비효율 개선을 위한 목표들이 상이한 것으로 나타났다. 본 연구 결과는 대학의 운영 효율성 제고와 경쟁력 강화에 기여할 것으로 기대되며, LINC+의 후속 사업 계획 수립에도 활용될 수 있을 것이다.
        8,300원
        53.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sensory evaluation of shucking pressure, pressure holding time, seeding method, difference in full shucking rate in the aquaculture area and shucking oyster was performed using an ultra-high pressure oyster shucking machine. The reaching time for each target pressure is 2.2-2.4 MPa/sec in the range of 180 MPa to 240 MPa. had a rate of pressure rise. There was a difference of 0.5-1.7℃ in the range of 24-27℃ in the seawater temperature before and after the pressure treatment inside the pressure vessel, but there was no specific increase or decrease in seawater temperature. When only the shucking pressure is increased without the pressure holding time, the critical shucking pressure at which the oyster shell is opened and the flesh is peeled in the range of 200 to 220 MPa. When the critical shucking pressure is reached, the oyster sample in the closed vessel is expected to be shucked by about 40%. If there is no pressure holding time when judged only by full shucking, an increase in pressure of about 1.5 MPa is required to further shuck 3% of the oyster population. The oyster samples cultivated in the south coast of Korea were subject to full shucking under the conditions of 220 MPa shucking pressure and two minutes (120 seconds) of pressure holding time, and the difference in the pressure of the oysters according to the oyster seeding method and the farming area was minute. Finally, the condition of 220 MPa of shucking pressure and three minutes of pressure holding time was the best at 1.52 when the result of the sensory evaluation performed manually was set to 1.0. Next was 1.4 under the conditions of 220 MPa of shucking pressure and one minute of pressure holding time (60 seconds), and 1.3 under the condition of 220 MPa and two minutes of pressure holding time (120 seconds). Therefore, it is considered that the most desirable shucking conditions, considering the efficiency and sensory evaluation results, are the conditions of 220 MPa shucking pressure and two to three minutes of pressure holding time.
        4,000원
        54.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 수출성과 결정요인의 주요 이론을 기반으로 메타분석을 수행하여 기업의 특성에 따른 주요한 수출성 과 결정요인의 차이와 연구 방법에 따른 효과크기 차이를 규명하고자 하였다. 이를 위해 1992년부터 2021년 6 월까지 수행된 한국 기업의 수출성과 관련 실증연구 197편으로부터 946개의 효과크기를 도출하였고 중소기업만 을 대상으로 142편 연구물의 651개 효과크기를 분석하였다. 분석결과, 첫째, 무선효과모형으로 분석한 한국 중소기업의 수출성과 결정요인의 전체 평균효과크기는 .336 (p < .001)으로 중간 수준 이상으로 나타났다. 둘째, 한국 중소기업의 수출성과 결정요인은 자원기반이론이 산 업조직론보다 효과크기가 더 큰 것으로 나타났으나 글로벌 금융위기 이후에만 차이가 있었다. 셋째, 일반기업과 벤처기업의 수출성과 결정요인은 차이가 있었으며 벤처기업은 해외시장특성과 경영진의 국제경험이 일반기업보다 효과크기가 더 크게 나타났다. 넷째, 정량적 수출성과 측정보다 정성적 수출성과 측정에 의한 효과크기가 상당히 크게 나타났다. 다섯째, 2차 자료에 비해 1차 자료를 사용한 효과크기가 더 크게 나타났다. 본 연구는 수출성과 결정요인에 관한 이론을 기반으로 메타분석을 수행함으로써 수출성과 분야의 단편적이고 다양하며 일관성 없는 문제를 해결할 수 있는 범주화 프레임과 방법론을 제시하였다는 점에서 학문적 의의가 있 다. 분석결과는 수출성과를 높이기 위한 기업의 전략 수립과 정부의 효과적인 수출지원정책 수립에 도움을 줄 것 으로 기대한다.
        8,600원
        55.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Complaints about foul odors are emerging as an issue, and the number of complaints is steadily increasing every year. Biofiltration is known to remove harmful or odorous substances from the atmosphere by using microorganisms, and full-scale biofilters are being installed and operated in various environmental and industrial facilities. In this study, the current status and actual odor removal efficiency of full-scale biofilters installed in publicly owned treatment facilities such as sewage, manure, and livestock manure treatment plants were investigated. In addition, the effects of design and operating factors on their efficiency were also examined. As a result, it was found that odor prevention facilities with less than 30% odor removal efficiency based on complex odors accounted for 40%-50% of the biofilters investigated. In investigating the appropriate level of operating factors on odor removal efficiency, it was found that compliance with the recommended values p lays a significant role in improving odor removal efficiency. In the canonical correlation analysis for the on-site biofilter operation and design data, residence time and humidity were found to be the most critical factors. The on-site biofilter operation and design data were analyzed through canonical correlation analysis, and the residence time and humidity maintenance were found to be the most important factors in the design and operations of the biofilter. Based on these results, it is necessary to improve the odor removal efficiency of on-site biofilters by reviewing the effectiveness of the operation factors, improving devices, and adjusting operating methods.
        4,600원
        56.
        2022.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Cu2ZnSn(SxSe1-x)4 (CZTSSe) absorbers are promising thin film solar cells (TFSCs) materials, to replace existing Cu(In,Ga)Se2 (CIGS) and CdTe photovoltaic technology. However, the best reported efficiency for a CZTSSe device, of 13.6 %, is still too low for commercial use. Recently, partially replacing the Zn2+ element with a Cd2+element has attracting attention as one of the promising strategies for improving the photovoltaic characteristics of the CZTSSe TFSCs. Cd2+ elements are known to improve the grain size of the CZTSSe absorber thin films and improve optoelectronic properties by suppressing potential defects, causing short-circuit current (Jsc) loss. In this study, the structural, compositional, and morphological characteristics of CZTSSe and CZCTSSe thin films were investigated using X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), and Field-emission scanning electron microscopy (FE-SEM), respectively. The FE-SEM images revealed that the grain size improved with increasing Cd2+ alloying in the CZTSSe thin films. Moreover, there was a slight decrease in small grain distribution as well as voids near the CZTSSe/Mo interface after Cd2+ alloying. The solar cells prepared using the most promising CZTSSe absorber thin films with Cd2+ alloying (8 min. 30 sec.) exhibited a power conversion efficiency (PCE) of 9.33 %, Jsc of 34.0 mA/cm2, and fill factor (FF) of 62.7 %, respectively.
        4,000원
        60.
        2022.10 구독 인증기관·개인회원 무료
        This study is to investigate fuel cladding temperature in a transport system for the purpose of developing a methodology for evaluating the thermal performance of spent fuel. Detailed temperature analysis in the transport system is important because the degradation mechanism of the fuel cladding is generally sensitive to temperature and temperature history. In such a system, the magnitude of the temperature change is determined by examining the temperature sensitivity of fuel assemblies and system components including fuel cladding temperature, considering the material properties, component specifications, component aging mechanism, and heat transfer mechanism. The sensitivity analysis is performed using heat transfer models by computational fluid dynamics for the horizontal transport system. The heat transfer within the system by convection, conduction and thermal radiation is calculated by thermal-hydraulic analysis code FLUENT. The calculation region is divided into a basket cell and a transport cask. The thermal analysis of the basket cell is for predicting the fuel cladding temperature. And the reason for analyzing the transport cask is to provide the boundary condition for the basket cell by reflecting the external environmental conditions. Here, the basket cell containing the spent fuel assembly is modeled on the homogeneous effective thermal conductivity. The purpose of this analysis is to evaluate fuel cladding temperatures for the following four main items. That is the effect of surface emissivity changes in basket due to the oxide layer of the fuel cladding, the effect of degradation of the canister backfill helium gas, the effect of fuel assembly position in basket cell on fuel cladding and basket temperatures in canister, and the effect of using the homogeneous effective thermal conductivity model instead of the fuel assembly in basket cell. As a result of the analysis, the maximum temperatures in basket cells are evaluated for the above four items. Thermal margins for each item are investigated for thermal performance requirements (e.g., peak clad temperature below 400oC).
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