• Carbon letters
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• 제26권
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• pp.66-73
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• 2018

We assessed the effects of combining bio-char with straw residue mulching on the loss of soil soluble nutrients and citrus yield in sloping land. The two-year study showed that straw residue mulching (ST) and bio-char application combined with straw residue (ST+BC) can significantly reduce soil soluble nutrient loss when compared with the control treatment (CK). The comparative volume of the soil surface runoff after each of the treatments was as follows: CK > ST > ST + BC. Compared with the CK, the runoff volume of the ST was reduced by 13.6 % and 8.5 % in 2014 and 2015, respectively. Compared with the CK, combining bio-char with the ST application reduced the loss of soluble nitrogen and improved the soil total nitrogen content reaching a significant level in 2015. It dramatically increased the soil organic matter content over the two year period (36.3% in 2014, 50.6% in 2015) as well as the carbon/nitrogen ratio (C/N) (16.6% in 2014 and 39.3% in 2015). Straw mulching combined with bio-char showed a trend for increasing the citrus yield.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1675-1680
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• 2000

Recently the uncertainty has been made rapid progress in various fields of industry but the uncertainty measurement method of acoustical test (i.e. Insertion loss, Absorption ratio, Transmission loss etc,) hasn't been established. In this study, the uncertainty of measurement method for ducted silencers is carried out according to ISO 7235. The standard uncertainty factors are composed of sound pressure level, microphone sensitivity and pistonphone calibration in this measurement. Sound pressure level is type A evaluation of uncertainty, microphone sensitivity and pistonphone calibration are type B evaluation of uncertainty. The combined standard uncertainty is calculated by two type evaluation. The expanded uncertainty is expressed by the combined standard uncertainty multiply k value which is yield the effective degree of freedom.

• 한국군사과학기술학회지
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• 제15권2호
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• pp.186-192
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• 2012

Noise is a major cause of hearing loss in the air base. There are lots of risk factors of hearing loss including noise, and hearing loss can be accelerated by combined effects of these risk factors. Here in, we reviewed risk factors of hearing loss, and analysed key risk factors inducing hearing loss in the air base. Risk factors exacerbating hearing loss with noise were mainly investigated in this research because noise could not be an avoidable risk factor in the air base. Analysed data will contribute to make green environment minimizing hearing loss of pilots and supporting personnels in the air base.

• 한국전자통신학회논문지
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• 제17권2호
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• pp.237-244
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• 2022

본 논문에서는 저층 고밀도 교외 환경에서 신호의 클러터 손실(Clutter loss)과 건물 인입 손실(Building entry loss)을 측정 후 분석했다. 선정된 환경에서 BEL, CL, BEL과 CL 결합 등 3가지 전파 모델을 측정하였다. 각 모델 측정 결과 바탕으로 BEL과 CL을 결합하였을 때의 수치를 분석했다. 각각 주파수에서 BEL과 CL 결합 측정값은 27.55dB 와 26.12dB 였으며, 계산값과 차이는 -4.19dB와 5.82dB였다. 측정이 건물 내부에서 이루어졌다는 점을 고려할 때 이러한 차이는 미미해 보인다. 따라서 BEL과 CL의 각각 측정값 합산과 결합 모델의 측정값을 비교하였을 때 -4.19dB와 5.82dB 오차를 도출하였고, 본 결과는 유사한 사례의 전파 모델 분석 시 참고 자료로 활용될 수 있을 것이다.

• 전기학회논문지
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• 제60권5호
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• pp.905-912
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• 2011

In this paper, the method on calculating benefits of combined heat and power is introduced for standard evaluation in electrical power system. This paper calculates benefits about new national viewpoint and viewpoint of independent power producers and assesses benefits of combined heat and power in Korea and In Seoul national capital area. Benefit costs are composed of avoid cost of centralized generation, line upgrading adjustment, loss adjustment and electrical power trade cost per year in earlier study, in addition trade cost of $CO_2$, construction cost of combined heat and power for accurate calculation. Benefit of combined heat and power is calculated by simulation results of real electrical power system.

• 대한중풍순환신경학회지
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• 제24권1호
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• pp.25-40
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• 2023

Background: Although not clarified, the overall prevalence of visual field loss after stroke was estimated at 52% of stroke survivors and for visual acuity loss, at 70% of them. Among visual field loss patients after stroke, homonymous hemianopia is the most common symptom. Visual defect degrades the quality of life by disrupting independent life and affecting the survival of the patients, but highly-evidenced treatment has not been found until now. ■Case report A 51-year-old female with left-side homonymous hemianopia and central vision loss by a right occipital-temporal hemorrhage was treated with Hyeolbuchukeo-tang, Ikgibohyeol-tang, acupuncture, electroacupuncture, and moxibustion. We used a confrontation visual field exam, automated perimetry and visual analog scale, and visual acuity test to observe changes in the patient's symptoms and evaluate the efficacy of the treatment. After 61 days of such interventions, the patient's subjective discomfort lessened, followed by positive changes in the scales of tests mentioned above. ■Conclusion This case suggests that combined Korean medicine treatment might be an effective tool for treating post-stroke homonymous hemianopia and central vision loss. More studies should be conducted to support the effectiveness of the treatment.

• 대한음성학회지:말소리
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• 제43호
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• pp.101-112
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• 2002

In real time packetized voice application, missing packets are major source of voice quality degradation. Thus packet loss concealment (PLC) algorithms are needed to guarantee QoS of VoIP. In this paper, we describe packet loss concealment scheme utilizing the next good frame which follows loss packets. When this scheme is combined with other PLC algorithms, such as G.711 pitch waveform replication recommended by ITU-T LP based PLC algorithm, additional voice quality improvement is obtained for consecutive packet loss larger than 60 msec.

• 한국유체기계학회 논문집
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• 제12권5호
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• pp.39-46
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• 2009

This paper outlines how the on-line performance monitoring system can be used to improve the efficiency and maintenance of the equipments. And a method of the heat rate allocation to each equipment was suggested to monitor the performance of combined cycle power plants. This calculates the expected heat rate of current conditions and compares it with actual values. Loss allocation in heat rate is reconciled by calculating the magnitude of the deficiency contributed by major components, such as the gas turbine, heat recovery steam generator, steam turbine and condenser. Expected power output is determined by a detailed model and correction curves of the plant. This simulation models are found to reproduce high accuracy in behavior of the cycle for various operating conditions, both in design and in off-design condition. Errors are lower than 2% in most cases.

• 한국식품과학회지
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• 제21권1호
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• pp.13-16
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• 1989

선택된 당류 및 전분 가수분해 물질을 기질로 사용하여 냉동건조에 의하며 acetaldehyde을 고정시키는 방법을 연구하였다. 단순기질 보다는 복합기질이 일반적으로 acetaldehyde를 고정시키는 능력이 좋았고. 특히 mannitol+lactose가 고정능력 면에서 가장 우수했다. 그리고 경계성 등을 고려할 때 mannitol+maltodextrin이 공업적으로 acetaldehyde를 고정하는데 적당할 것으로 평가됐다. 일반적으로, 기질 농도가 증가함에 따라 건조 중 acetaldehyde손실이 감소하였으며, 기질 농도 40%일 때 mannitol+maltodextrin 기질의 acetaldehyde 고정 능력이 가장 좋았다. 냉동건조 방법으로 acetaldehyde를 고정할 경우 건조실 압력이 낮을수록 건조 중 acetaldehyde 손실이 감소했다. 그러나 대량생산을 목적으로 할 때에는 0.5 Torr이하의 압력을 유지하는데 건조경비 부당이 과다하므로, 0.5 Torr정도의 건조실 압력을 유지하는 것이 적당할 것으로 평가됐다.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1698-1711
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• 2022

A combined safety approach, which uses a best-estimate computer code and adopts conservative assumptions for safety systems availability, is developed and applied to the safety margin evaluation for the Loss of Condenser Vacuum (LOCV) of the 1000 MWe Korean Nuclear Power Plant. The Multi-dimensional Analysis of Reactor Safety-KINS standard (MARS-KS) code is selected as a best-estimate code and the PAPIRUS program is used to obtain different initial operational conditions through random sampling of control variables. During an LOCV event, fuel integrity is not threatened by the increase in Departure from Nuclear Boiling Ratio (DNBR). However, the high pressure in the primary coolant system and the secondary system might affect the system integrity. Thus, the peak pressure becomes a major safety concern. Transient analyses are performed for 124 cases of different initial conditions and the most conservative case, which results in the highest system pressure is selected. It is found the suggested methodology gives similar peak pressures when compared to those predicted from existing methodologies. The proposed approach is expected to minimize the time and efforts required to identify the conservative plant conditions in the existing conservative safety methodologies.