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        검색결과 116

        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For motor controller designers, building a simulation environment is not a difficult process. After verifying the controller by simulation, it is common to select 20kHz for the current control loop, 1kHz for the speed loop, and 100Hz for the position loop when implementing the actual HW embedded system. This is because maximized cycles (20kHz) for each control loop are unnecessary in control theory and are a waste of cost and HW resources. However, in a simulation environment, each loop will often have the same control cycle (20kHz maximum). This is because we think it is unnecessary to reflect this part in the simulation. In this paper, it is shown that the difference in the sampling time of each control loop makes a big difference in the simulation result, and as a solution, it is proposed to apply LPF to the position loop output stage. In the process, the reasons for the differences were analyzed, and the effect of LPF, the reason for application, and the feasibility of implementation were proved by actual software coding.
        4,000원
        3.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 시가독소 생성 대장균(STEC)을 검출하 기 위해 식품공전의 polymerase chain reaction (PCR)검사 법과 loop-mediated isothermal amplification (LAMP)를 비 교하였다. PCR 및 LAMP의 검출 한계(LOD) 및 정량화 한계(LOQ), 민감도, 특이성 및 효율성을 평가하기 위해 다 양한 식품에 STEC를 접종하였다. LOD는 PCR의 경우 104 CFU/mL 이하, LAMP의 경우 103 CFU/mL 이하로 측정되 었다. LOQ 값은 PCR과 LAMP 간에 차이가 없었다. 그러 나 4가지 식품군에서 민감도는 양념육이 최대 11.1%, 간 소고기가 최소 8.1% 차이가 났다. LAMP는 네 가지 음식 유형 모두에 대해 높은 민감도와 100% 특이도를 보였다. 따라서 LAMP는 식품 유형에 따라 검출률이 비슷하고 특 이도와 민감도가 식품공전 PCR보다 우수하기 때문에 STEC 에 대한 신뢰할 수 있는 분자 검출 방법이다.
        4,000원
        4.
        2023.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigated an emerging magnetic loop dynamically formed on the Sun, which has the effective footpoint heating source that may play a key role in heating a solar atmosphere with free magnetic energy in it. It is suggested that the heating source could be related to local compression of a plasma in the emerging loop by means of Lorentz force, which converts the magnetic energy to the internal energy of the plasma that is used to reaccelerate a decelerated downflow along the loop, eventually generating the source when the kinetic energy of the downflow is thermalized. By analyzing very high-cadense data obtained from a magnetohydrodynamic simulation, we demonstrate how the local compression is activated to trigger the generation of the heating source. This reveals a characteristic of the emerging loop that experiences a dynamic loop-loop interaction, which causes the local compression and makes the plasma gain the internal energy converted from the magnetic energy in the atmosphere. What determines the characteristic that could distinguish an illuminated emerging loop from a nonilluminated one is discussed.
        4,000원
        6.
        2022.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To seek an atmospheric heating mechanism operating on the Sun we investigated a heating source generated by a downflow, both of which may arise in a magnetic loop dynamically formed on the Sun via flux emergence. Since an observation shows that the illumination of evolving magnetic loops under the dynamic formation occurs sporadically and intermittently, we performed a magnetohydrodynamic simulation of flux emergence to obtain a high-cadence simulated data, where temperature enhancement was identified at the footpoint of an evolving magnetic loop. Unlike a rigid magnetic loop with a confined flow in it, the evolving loop in a low plasma β atmosphere is subjected to local compression by the magnetic field surrounding the loop, which drives a strong supersonic downflow generating an effective footpoint heating source in it. This may introduce an energy conversion system to the magnetized atmosphere of the Sun, in which the free magnetic energy causing the compression via Lorentz force is converted to the flow energy, and eventually reduced to the thermal energy. Dynamic and thermodynamic states involved in the system are explained.
        4,000원
        7.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        타임루프는 등장 인물에게 반복되는 시간의 주기를 경험하게 하는 장치로, 주기적 시간에서의 반복적 실패 를 통해서 문제를 파악하고 해결하는 과정이 드러나 있는 것이 특징이다. 본 논문에서는 타임루프 장치를 통한 반복이 게임의 전개와 플레이어의 경험에 어떤 작용을 하는지 알아보기 위해 게임 ‘12 Minutes’을 중심 으로 게임요소와 스토리텔링을 살펴보았다. 이를 위해 게임에서 타임루프로 인지되는 인터랙션이 무엇이고, 그 안에서 플레이어 캐릭터와 플레이어의 위치, 게임의 목표와 분기점이 어떻게 변화하는지 분석하였다. 그 결과, 다음과 같은 사실을 알게 되었다. 첫째, 타임루핑 게임에서 반복적 인터랙션은 오브젝트와 플레이어, 캐릭터 사이에 일어나는데, 루핑을 알고 있는 존재는 플레이어 캐릭터와 플레이어로 타임루핑은 플레이어 차원과 플레이어 캐릭터 차원에서 일어난다는 점이다. 둘째, 게임에서 타임루프는 다중의 서사를 만들어내 는 플랫폼으로 문제해결을 위한 다양한 시도가 가능하고, 플레이어가 가상 세계에 행하는 행위를 통해 자신 의 욕망하는 바를 잘 드러낼 수 있도록 기능하는 장치라는 것이다.
        4,000원
        8.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Test of the operating characteristics and energy saving performance of a container cooling system that reduces the operating energy of a refrigeration system using a loop thermosyphon heat exchanger that removes heat by temperature difference between outdoor and indoor was performed. As a result of the experiments, when the loop thermosyphon and the refrigeration system were operated simultaneously, the refrigeration system operated intermittently by reducing the heat load. As the temperature difference between indoor and outdoor increased, the operating time of the refrigeration system decreased and the energy efficiency rate increased. Energy efficiency rate showed a tendency to increase with increasing temperature difference, and the predicted correlation of energy efficiency rate using the performance of the loop thermosyphon heat exchanger and the refrigeration system was relatively consistent with the experimental value.
        4,000원
        10.
        2022.05 구독 인증기관·개인회원 무료
        At high temperatures, molten salt has heat transfer properties like water. Molten salt has the characteristics of a strong natural circulation tendency, large heat capacity, and low thermal conductivity. Unlike sodium, molten salt does not react explosively exothermically with air. However, molten salt has a strong tendency to corrode materials, and its properties are easily changed by a sensitive reaction to oxygen and moisture. Therefore, it is necessary to study material corrosion properties and chemical control methods for nuclear fuel salts, which are eutectic mixtures. In this study, the optimal operation method of the thermal convection loop is established to perform the experiments on the molten salt. The process describes briefly as follows. The operation step consists of preparation, purification, transportation, and operation. In the preparation, the step checks the entire structure and equipment (TC, blower, vacuum pump, etc.). And melt the salt mixture at a high temperature (670°C) slowly in the purification step. Before injecting the molten salt, the surface temperature of the entire loop must retain temperature (about 500°C) constantly. Completely melted molten salt in the melting pot is flow along the pipe of the thermal convection loop in the transportation step. Lastly, the convection of molten salt goes to keep by the temperature difference. The thermal convection loop can be utilized for various experiments such as corrosion tests, component analyses, chemistry control, etc.
        13.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        백한우는 한우에서 유래되었으며, 모색과 망막에 색소가 전혀 없는 전형적인 알비노 증상을 보인다. 본 연구는 mtDNA D-loop 영역 전체 서열에 기초하여 백한우의 모계유전특성을 분석하기 위해 수행하였다. 백한우에서 특이적으로 나타나는 TYR 유전자 exon 2 영역의 염기변이를 PCR-RFLP 분석을 통해 확인하였다. 이 결과를 통해서 본 연구에서 공시한 32두 모두 백한우임을 확인하였다. 백한우 32두에 대한 mtDNA D-loop 영역 전체 서열을 이용하여 염기변이 및 유전적 다양성을 확인하였다. A, T, C, G 염기 각각의 빈도는 32.8, 28.9, 24.4 및 13.9%, GC 함량은 38.3%로 확인되었으며, 이러한 빈도는 타 소품종들과 유사하였다. 또한 9개의 다형부위가 확인되었고, 6개의 haplotype으로 분류되었다. haplotype 다양성지수는 0.651, 염기변이율은 0.00181로 확인되었으며, 기존에 보고된 다른 소품종들보다 낮은 수치를 보였다. 염기변이 양상 비교 및 계통유전학적 분석 결과, 백한우에서 나타난 6개의 haplotype은 T1 및 T3 haplogroup으로 분류되었으며, 특히 5개 haplotype이 T3 haplogroup에 포함되었다. 본 연구의 결과는 백한우의 보존, 관리 및 활용을 위한 중요한 자료로 활용될 수 있을 것으로 사료된다.
        4,000원
        14.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Considering the features of body repair for automotive body where same damage and repair conditions does not exist in car accident, it is essential to acquire know-how and continuously approach new materials and new technologies on the site of maintenance where the theoretical instruction of textbook cannot react accurately minute by minute. Especially, in case of car repair from unexpected accidents such as body repair or dent repair, it is difficult to satisfy vehicle owners despite their request. Accordingly, this study researched the better maintenance technology to restore to its original state with more improved technology as vehicle owners wish. This study made time to repair reduced by 98% and the cost reduced by 79.6% through the accurate diagnostic technique before repair and maintenance technologies of body crash analysis applying property of high-speed tensile. It also obtains intangible effects including prevention of environmental pollution and maximization of vehicle owners satisfaction.
        4,000원
        18.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Experiments were conducted to evaluate the performance factors such as type of working fluid, flow direction, arrangement and stage of loop thermosyphon heat exchanger for ESS battery container cooling. Pentane showed slightly better performance of the heat exchanger than R-134a as a working fluid. Driving the fan in the suction direction showed improved performance compared to the blowing direction. The two-stage heat exchanger increased the heat transfer rate by more than 30% at the same temperature difference compared to the single-stage heat exchanger. Also, the counterflow flow showed better performance than the parallel flow in the two-stage heat exchanger.
        4,000원
        19.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Experiments were conducted on the operating characteristics and performance of various types of working fluid, filling amount and heat flow rate of a loop thermosyphon for cooling ESS battery container. As results of performance test on various working fluids, HFE-7100 and R-134a as a working fluids showed unstable operating and low performance due to vapor pressure drop, and performance was improved by increasing the number of vapor lines for reducing a pressure drop. In this study, n-pentane was more stable and showed better thermal performance among various working fluids.
        4,000원
        20.
        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
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