• 한국작물학회지
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• 제49권1호
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• pp.25-29
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• 2004

The responses of soybean seeds were evaluated to accelerated aging and gamma irradiation with regard to germination, seed leakage, seed leachate component and dry weight of hypocotyl and primary root of the germinating seed. Accelerated aging significantly reduced the final germination rate while gamma irradiation increased the final germination rate. Furthermore, the interactive effects occurred that the final germination rate of 5-day aged seeds increased considerably in response to 4 Gy of gamma irradiation. The extent to which the electrolyte was leaked from the seeds (conductivity) was significantly affected by accelerated aging and showed a close negative correlation with the germination rate. Gamma irradiation, however, did not significantly affect the electrical conductivity of seed leachate. The accelerated aging significantly increased the concentrations of the particular electrolytes leaked from the seeds while the gamma irradiation did not affect those concentrations. Of the electrolytes leaked from the seeds, Ca and Mg showed relatively lower concentrations while K showed greater concentrations than others. Moreover, N and P showed similar responses to aging treatment. Aging treatment significantly affected dry weight (DW) of hypocotyls and primary root. Also, gamma irradiation decreased DW of hypocotyls and primary root, particularly for 8 Gy associated with 5 days aging treatment. The data were discussed in terms of the relationships of seed vigor with aging treatment and gamma irradiation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1003-1005
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• 2003

In this paper, 3-D nonlinear electromagnetic analysis of a single phase 1MVA 22.9 kV/6.6 kV high temperature superconducting(HTS) transformer with double pancake windings was accomplished. The characteristics of 1MVA HTS transformer such as The efficiency, voltage regulation and % impedance voltage drop were obtained by the 3-D non-linear electromagnetic analysis. And in order to verify the 3-D non-linear electromagnetic analysis of a single phase 1MVA HTS transformer, a 1MVA test transformer with windings made of copper tapes with the same size as BSCCO-2223 HTS tape was manufactured. The energy conservation method to perform the analysis of leakage impedances of both a 1MVA HTS transformer and test transformer was used. The characteristic analysis such as efficiency, voltage regulation and % impedance voltage drop of transformer was performed. And the obtained values of both 1MVA HTS transformer and test transformer were compared.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.893-899
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• 2024

In a secondary cooling system of a sodium-cooled fast reactor (SFR), rapid detection of hydrogen due to sodium-water reaction (SWR) caused by water leakage from a heat exchanger tube of a steam generator (SG) is important in terms of safety and property protection of the SFR. For hydrogen detection, the hydrogen detectors using atomic transmission phenomenon of hydrogen within Ni-membrane were used in Japanese proto-type SFR "Monju". However, during the plant operation, detection signals of water leakage were observed even in the situation without SWR concerning temperature up and down in the cooling system. For this reason, the study of a new hydrogen detector has been carried out to improve stability, accuracy and reliability. In this research, the authors focus on the difference in composition of hydrogen and the difference between the background hydrogen under normal plant operation and the one generated by SWR and theoretically estimate the hydrogen behavior in liquid sodium by using ultra-accelerated quantum chemical molecular dynamics (UA-QCMD). Based on the estimation, dissolved H or NaH, rather than molecular hydrogen (H₂), is the predominant form of the background hydrogen in liquid sodium in terms of energetical stability. On the other hand, it was found that hydrogen molecules produced by the sodium-water reaction can exist stably as a form of a fine bubble concerning some confinement mechanism such as a NaH layer on their surface. At the same time, we observed experimentally that the fine H₂ bubbles exist stably in the liquid sodium, longer than previously expected. This paper describes the comparison between the theoretical estimation and experimental results based on hydrogen form in sodium in the development of the new hydrogen detector in Japan.

• KIEAE Journal
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• 제3권3호
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• pp.43-50
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• 2003

Nowdays the apartment is a main type of modernized residential buildings. According to the improvement of construction techniques and functions of windows and doors, recent apartments are enhanced air tightness of windows, doors and building envelopes. As Infiltration is decreased and natural ventilation is reduced, energy could be saved in winter. However, indoor air quality is bad. The air Infiltration of a building could be enlarged by physical actions, such as building designs, constructions and reduction of air tightness which is caused by aging. This research analyzes and measures with KNS-4000P (Sapporo air tightness measurement) the air tightness of the high rise apartments which is recently constructed and not occupied yet. With depressurization method, the KNS-4000 installed on the window and the indoor air-leakage was measured. At that time, Air come out from the edge of the windows and doors because of the pressure differences between indoor and outdoor. We measure the amount of the air as effective air leakage areas. This method of depressurization takes less time to measure than other methods and is less affected from other conditions. We measured infiltration of total 56 household, 29 households S apartment (total floor area : $64.42m^2$) in Balan and 29 households D apartment(total floor area : $78.21m^2$) in Chonan. As a result of the field measurements at October 2003, normalized leakage area of D apartment in Cheonan was $2.05cm^2/m^2{\sim}3.49cm^2/m^2$ (average: $2.77cm^2/m^2$) and normalized leakage area of S apartment in Balan is $1.23cm^2/m^2{\sim}1.68cm^2/m^2$ (average: $1.5cm^2/m^2$).

• 한국가스학회지
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• 제12권2호
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• pp.7-11
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• 2008

본 논문은 LPG 차량의 주행거리에 따른 스템시일의 오일누설 특성에 대한 실험적 연구결과를 제공하고자 한다. 캠축의 속도와 오일의 온도가 증가하여도 40,000 km 이하의 주행거리를 갖는 스템시일에서는 엔진오일의 누설에 큰 영향을 미치지 못하는 것으로 나타났다. 반면에 주행거리가 50,000 km 이상 100,000 km 정도에서 사용한 스템시일의 경우는 스템시일의 밀봉성에 영향을 미쳐 누설이 급격하게 증가하는 것으로 나타났다. 이것은 포핏밸브와 스템시일 사이의 미끄럼마찰 접촉면을 따라서 오일이 누설되기 때문에 발생한 것이다. 실험결과에 의하면, 현재 LP차량에서 사용하고 있는 스템시일은 주행거리가 $50,000{\sim}60,000\;km$ 정도에서 교환하는 것이 누유특성을 고려하면 바람직하다. 따라서 포핏밸브의 누유를 차단하기 위해 사용하고 있는 스템시일은 보다 향상된 내구성과 수명연장을 위해 재설계되어야 한다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권1호
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• pp.80-90
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• 2016

Thanks to superior leakage energy efficiency compared to SRAM cells, STTRAM cells are considered as a promising alternative for a memory element in on-chip caches. However, the main disadvantage of STTRAM cells is high write energy and latency. In this paper, we propose a low-cost write filter (WF) cache which resides between the load/store queue and STTRAM-based L1 data cache. To maximize efficiency of the WF cache, the line allocation and access policies are optimized for reducing energy consumption of STTRAM-based L1 data cache. By efficiently filtering the write operations in the STTRAM-based L1 data cache, our proposed WF cache reduces energy consumption of the STTRAM-based L1 data cache by up to 43.0% compared to the case without the WF cache. In addition, thanks to the fast hit latency of the WF cache, it slightly improves performance by 0.2%.

• International journal of advanced smart convergence
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• 제7권3호
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• pp.92-100
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• 2018

In this paper, we propose a fault-tolerant scheduling scheme with energy efficiency for real-time periodic tasks on DVFS-enabled multicore processors. The scheme provides the tolerance of a permanent fault with the primary-backup task model. Also the scheme reduces the energy consumption of real-time tasks with the fully overlapped execution between each primary task and its backup task, whereas most of previous methods tried to minimize the overlapped execution between the two tasks. In order to the leakage energy loss of idle cores, the scheme activates a part of available cores with rarely used cores powered off. Evaluation results show that the proposed scheme saves up to 82% energy consumption of the previous method.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권3호
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• pp.330-338
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• 2016

Phase change memory (PCM) has been studied as an emerging memory technology for last-level cache (LLC) due to its extremely low leakage. However, it consumes high levels of energy in updating cells and its write endurance is limited. To relieve the write pressure of LLC, we propose a delta value indicator (DVI) by employing a small cache which stores the difference between the value currently stored and the value newly loaded. Since the write energy consumption of the small cache is less than the LLC, the energy consumption is reduced by access to the small cache instead of the LLC. In addition, the lifetime of the LLC is further extended because the number of write accesses to the LLC is decreased. To this end, a delta value indicator and controlling circuits are inserted into the LLC. The simulation results show a 26.8% saving of dynamic energy consumption and a 31.7% lifetime extension compared to a state-of-the-art scheme for PCM.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 춘계학술발표논문집
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• pp.267-270
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• 2003

All artificial infernal organs which are using electric energy supply energy with inductive couple. Transcutaneous energy transmission system enhance survival chance of the patients and quality of life by reducing volume and mass. In this research, we used both tune in transmission system in state of fixing cycle in order to increase the voltage gain and the current gain and to reduce effect of leakage inductance. Also to maximize the effect of resonance, a constant frequency duty cycle control method is used. Test is progressed with litz wire which is set up with various sizes of core to minimize size of converter. This research aimed in analysis of transcutaneous energy transmission system and in measuring of stability and efficiency of Lithium-ion battery charge which are using transmitted energy.

• 대한전자공학회논문지SD
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• 제38권10호
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• pp.678-686
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• 2001

CaAs metal semiconductor field effect transistor (MESFET) 소자의 전달컨덕턴스 분산 (transconductance dispersion) 현상과 게이트 누설 전류의 원인을 capacitance deep level transient spectroscopy (DLTS) 측정을 이용하여 해석하였다. DLTS 스펙트럼에서는 활성화 에너지가 각각 0.65×0.07 eV와 0.88 × 0.04 eV인 두개의 표면 결함과 0.84 × 0.01 eV의 활성화 에너지를 갖는 EL2를 관찰하였다. 전달컨덕턴스 분산 측정 결과, 전달컨덕턴스는 5.5 Hz ∼ 300 Hz의 주파수 영역에서 감소하였다. 전달컨덕턴스 분산을 온도의 함수로 측정한 결과, 온도가 증가할수록 전이 주파수는 증가하였고 전이 주파수의 온도 의존성으로부터 0.66 ∼ 0.02 eV의 활성화 에너지를 구할 수 있었다. 게이트 누설 전류 측정에서는 0.15 V 이하의 게이트 전압에서 순 방향과 역 방향 게이트 전압이 일치하는 오믹 전류-전압 특성을 나타내었고 게이트 누설 전류의 온도 의존성으로부터 구한 활성화 에너지는 0.63 ∼ 0.01 eV로 계산되었다. 서로 다른 방법으로 구한 활성화 에너지의 비교로부터 표면 결함 H1이 주파수에 따라서 감소하는 전달컨덕턴스 분산 및 게이트 누설 전류의 원인임을 알 수 있었다.