• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.98-101
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• 2000

On CELP type Vocoders G.723.1 6.3kbps/5.3kbps Dual Rate Speech Codec, which is developed for Internet Phone and videoconferencing, uses VAD(Voice Activity Detection)/CNG (Comfort Noise Generator) in order to reduce the bit rate in a silence period. In order to reduce the bit rate effectively in this paper, we first set the boundary condition of the energy threshold to prevent the consumption of unnecessary processing time, and use three decision rules to detect an active frame by energy, pitch gain and LSP distance. To evaluate the performance of the proposed algorithm we use silence-inserted speech data with 0, 5, 10, 20dB of SNR. As a result when SNR is over 5dB, the bit rate is reduced up to about 40% without speech degradation and the processing time is additionally decreased.

• 한국융합학회논문지
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• 제8권1호
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• pp.19-23
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• 2017

전력은 모든 나라에서 사회 발전과 경제 성장에 가장 기본적인 자원이다. 산업이 고도화 되고 경제의 규모가 발전하면서 전력의 소비량은 점점 증가하고 있다. 전력을 공급하는 쪽에서는 전력을 생산할 때 자원의 낭비를 줄이기 위해 전력 사용량을 예측하는 것은 중요한 일이다. 또한 전력 수요 예측을 통해 여름과 겨울의 피크 타임에서의 전력 수요를 분산하는 것이 가능하다. 그리고 소비 전력의 예측은 국내에서 수요자원 거래시장(Negawatt market)이 본격화되면서 더욱 중요하게 되었다. 더구나 전력 소비량 예측은 소비자가 전력 시장에 직간접적으로 참여하는 수요관리 방법을 제공해준다. 본 연구에서는 1999년부터 2011년까지의 국내총생산, 1인당 국민총소득, 부가세, 국내전력소비량을 이용하여 제주도의 어업 전력 사용량을 예측하는데 유전자 알고리즘을 사용하고 있다. 유전자 알고리즘은 다양한 조합 최적화 분야에서 최적해를 찾는데 유용하게 사용되는 알고리즘이다. 본 논문에서 유전자 알고리즘에서 최적의 동작을 위한 파라미터들을 찾는다. 그리고 실제 전력 소비량 예측을 위해 사용되는 계수(coefficient)들의 최적값을 찾아 예측값과 실제 전력 소비량의 오차를 최소화하는데 목적이 있다.

• 한국수산과학회지
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• 제53권4호
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• pp.620-627
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• 2020

Oxygen consumption and blood physiology of olive flounder Paralichthys olivaceus (mean body weight 106.6±6.8 g, mean±SD) was investigated at salinities of 34.0 (control), 33.7, 33.3, 32.6, 31.3, 28.6, 23.1, 12.2 and 0.0 psu at 20.0℃, respectively. Stepwise salinity changes (34.0→33.7→33.3→32.6→31.3→28.6→23.1→12.2→0.0 psu) with an interval of 24 h for each salinity induced a significant (P<0.05) increase of oxygen consumption rate (OCR) in fish exposed from 31.3 to 0.0 psu compared to that of control fish. The maximum OCR was found in fish exposed to 23.1 psu, which was accompanied by 36.2% higher energy consumption than the control fish. Fish exposed to each salinity for 24 h induced a significant decrease of blood plasma Na⁺ in 0.0 psu and Cl^- in 12.2 and 0.0 psu (P<0.05), and increase of plasma glutamic oxaloacetic transaminase (GOT) in 0.0 psu compared to the control fish (P<0.05). The results of this experiment show that P. olivaceus exposed to concentrations below 31.3 psu requires more energy costs to adapt to salinity changes than 34.0 psu under our experimental conditions.

• 조명전기설비학회논문지
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• 제28권9호
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• pp.20-27
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• 2014

The power consumption pattern of high-speed railway has rarely during night time. But, during service time, the power is consumed irregularly related to train operation. Especially certain unusual about 1-2 days of service time interval to indicate the power consumption is rapidly growing phenomenon, which causes the capacity of the power contract is the annual electricity bill to rise rapidly as the cause. Normally, amount of peak power consumption bill rate at railway substation is over 20% of total electrical bill. Therefore, high-speed railway substation is expected to be considerably larger savings by reducing the peak power of the default charge(demand power).

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권4호
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• pp.462-466
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• 2010

본 논문은 하드디스크와 NAND 플래시메모리를 동시에 사용하는 저장 시스템 환경에서 전력 소모를 최소화하는 버퍼 캐쉬 관리 기법을 제안한다. 저장장치별 전력 소모율과 입출력 연산 종류(읽기 또는 쓰기) 및 블록의 재참조 가능성(최근성 및 빈도)을 통합적으로 고려하는 버퍼 캐쉬 관리 기법의 설계로 저장 시스템의 전력 소모량을 평균 18.0%, 최대 58.9%까지 줄일 수 있음을 보인다.

• Journal of Biosystems Engineering
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• 제36권3호
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• pp.223-230
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• 2011

Physiological signals such as body temperature, heart rate, blood pressure and heart rate variability and biomechanical workload for stress analysis were investigated during the cherry tomato harvesting work in a greenhouse. The skin temperatures raised $0.05^{\circ}C$/min, $0.03^{\circ}C$/ min, and $0.08^{\circ}C$/min in standing, stooping and squatting postures, respectively. Breath rate significantly increased from 18 to 28 breaths/min during the cherry tomato harvesting work. As the heart rate during the work ranged from about 72 to 110 beats/min (bpm), the cherry tomato harvesting work appeared to be a light intensity task of less than 110 bpm. The worker's average energy consumption rate in three positions during 43 min working time was 65.74 kcal (91 kcal/h in 70 kg). This was a light intensity of work, compared to 75 kcal/h in 70 kg of basic metabolic energy consumption rate of a worker with 70 kg weight; The maximum shear force on the disk (L5/ S1) due to static workload in the cherry tomato harvesting work was 446 N in the stooping posture, 321 N in the squatting posture and 287 N in the standing posture. Acute stress index expressed with the heart rate variability, increased parasympathetic activation up to about 70 while workers were doing most agricultural work in this study. This study provided a system to measure quantitatively workers' physiological change, kinematics and kinetic factors without any restrictions of space in the greenhouse works.

• Journal of Biosystems Engineering
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• 제36권4호
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• pp.273-278
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• 2011

This study was carried out to define the optimum drying conditions for Lycium chinense Miller as a useful healthy food, because recently the cultivation area and yield of this fruit are increased. The experiments of two varieties were performed at the temperature of $45^{\circ}C$, $50^{\circ}C$, $55^{\circ}C$ and $60^{\circ}C$. The drying ratio was the slowest and quality was the best at the drying temperature of $45^{\circ}C$. The drying temperature was higher, drying ratio was more faster and the quality became worse. The difference of drying ratios between the varieties was insignificant. The energy consumption per hour was the minimum at the drying temperature of $45^{\circ}C$, but the total energy consumption was the maximum for the long drying time. Also, the energy consumption at the drying temperature $50^{\circ}C$, $55^{\circ}C$ and $60^{\circ}C$ was not very different from others. Considering the drying ratio, quality and energy consumption, the drying time of 36 hours at the drying temperature of $50^{\circ}C$ was the most optimum condition.

• 설비공학논문집
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• 제27권6호
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• pp.328-336
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• 2015

Currently, 22% of the total energy consumption of buildings in Korea is used for lighting. Light-shelves have garnered attention as a way to reduce consumption, but there are few studies on the types of curve and curvature, which limits the improvement of light-shelf performance and its design. This study constructed a test bed of actual residential types to evaluate the performance. Outcomes of light usage, according to variables of light-shelves, were used as indicators of performance evaluation. The results are as follows:1) Performance evaluation was conducted on flat-type light-shelves to verify performance of curvature-shelves, which are movable with a width of 200 mm, and the most ideal angle and specification per solar term are calculated. 2) The (-) shaped curvature contributed to a reduction in energy consumption and an improvement of evenness. 3) In case of light-shelves with (-) shaped curvature, an increased angle not exceeding $80^{\circ}$ of the arc contributed to an improvement of light penetration. 4) Appropriate specifications of curved light-shelves include movable types with widths of 200 mm, and angle ranges of $20^{\circ}{\sim}60^{\circ}$. 5) Light energy consumption of a movable light-shelf with curvature and width of 200 mm were reduced by 17% and 7.8% compared to a $0^{\circ}$ fixed and a movable light-shelf, respectively.

• The Journal of Korean Physical Therapy
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• 제11권2호
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• pp.43-50
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• 1999

The purpose of this study was to evaluate the change of the energy consumption when loading to leg of the 60persons who don't have past history of cardiopulmonary and neuromuscular disease, To evaluate the change or energy consumption, heart rate was measured in sitting position for 5minute, during walking for 3minute at for 4.8km on treadmill, and during resting state after walking with 1Kg loading to right ankle, and the other 1Kg loading was added to left ankle and then heart rates were measured in the The results were as follow; 1. PCI value without loading to Ankle were significantly increased compared to 1Kg, and 2Kg. (p<0.05) 2. Female Subjects showed mon increased PCI value in without leading and 2Kg loading compared to male subjects. ( p<0.05) 3. When 1Kg ana 2Ka loading to ankle significantly differences were showed between them. (p<0.05) 4. In the case of 1Kg and 2Kg loading, the difference among age groups was observed and the significant difference among PCI, PCI 1kg, PCI 2kg was showed in the only group that is less than 30 years old. 5. In every PCI condition the difference among height groups was observed and the significant difference among PCI conditions was showed in the only group that is less than 165cm. 6. The difference among weight groups in each PCI condition was not observed, but the significant differences among PCI conditions was showed in every group except the group that h from 60kg to 69kg. These results showed that energy consumption was increased according to loading on the ankle during Sate so weight of orthosis or prosthesis met be considered when choosing them and during gait training with these ones.

• 청정기술
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• 제20권3호
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• pp.241-250
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• 2014

본 논문에서는 싸이클론 청소기들의 성능 및 환경성 평가를 실시하고, 결과를 분석하여 환경에 대한 영향을 최소화하기 위한 개선방안에 대하여 연구하였다. 환경성 평가에는 제품의 원재료 취득, 제조, 운송, 사용 및 폐기 과정에 대해서 제품이 환경에 미치는 영향을 정량적으로 평가하는 전과정 평가(life cycle assessment, LCA)를 간략한 형태로 이용하였다. 2가지의 싸이클론 청소기의 성능을 각 제품의 전력량, 흡입력, 소음, 온도를 관련 규정에 따라 측정하여 비교하였으며, 환경성 평가를 통해 전과정 중 사용단계의 에너지 소모가 가장 많다는 결과를 얻었다. 이를 바탕으로 사용단계의 에너지 소모를 줄이기 위해 싸이클론 청소기 내부에 배플(baffle)을 설치하고, 유지/소모품인 필터의 교환 주기를 늘려 사용단계의 에너지를 감소시키는 개선 방안을 제안하였다. 또한, 싸이클론 청소기의 불필요한 원료 물질 및 부품을 제거하고 상대적으로 재활용률이 높은 원재료 물질로 대체하는 방안을 고려하여 청소기의 중량은 줄이고, 재활용률은 높여 전과정에 대한 에너지 소비를 낮춘 친환경 청소기에 관하여 연구하였다.