• 산업경영시스템학회지
• /
• 제43권2호
• /
• pp.1-13
• /
• 2020

There are several methods of peak-shaving, which reduces grid power demand, electricity bought from electricity utility, through lowering "demand spike" during On-Peak period. An optimization method using linear programming is proposed, which can be used to perform peak-shaving of grid power demand for grid-connected PV+ system. Proposed peak shaving method is based on the forecast data for electricity load and photovoltaic power generation. Results from proposed method are compared with those from On-Off and Real Time methods which do not need forecast data. The results also compared to those from ideal case, an optimization method which use measured data for forecast data, that is, error-free forecast data. To see the effects of forecast error 36 error scenarios are developed, which consider error types of forecast, nMAE (normalizes Mean Absolute Error) for photovoltaic power forecast and MAPE (Mean Absolute Percentage Error) for load demand forecast. And the effects of forecast error are investigated including critical error scenarios which provide worse results compared to those of other scenarios. It is shown that proposed peak shaving method are much better than On-Off and Real Time methods under almost all the scenario of forecast error. And it is also shown that the results from our method are not so bad compared to the ideal case using error-free forecast.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제9권2호
• /
• pp.160-176
• /
• 2017

The interaction of focused wave groups with a vertical wall is investigated based on the second order potential theory. The NewWave theory, which represents the most probable surface elevation under a large crest, is adopted. The analytical solutions of the surface elevation, velocity potential and wave force exerted on the vertical wall are derived, up to the second order. Then, a parametric study is made on the interaction between nonlinear focused wave groups and a vertical wall by considering the effects of angles of incidence, wave steepness, focal positions, water depth, frequency bandwidth and the peak lifting factor. Results show that the wave force on the vertical wall for obliquely-incident wave groups is larger than that for normally-incident waves. The normalized peak crest of wave forces reduces with the increase of wave steepness. With the increase of the distance of focal positions from the vertical wall, the peak crest of surface elevation, although fluctuates, decreases gradually. Both the normalized peak crest and adjacent crest and trough of wave forces become larger for shallower water depth. For focused wave groups reflected by a vertical wall, the frequency bandwidth has little effects on the peak crest of wave elevation or forces, but the adjacent crest and trough become smaller for larger frequency bandwidth. There is no significant change of the peak crest and adjacent trough of surface elevation and wave forces for variation of the peak lifting factor. However, the adjacent crest increases with the increase of the peak lifting factor.

• Journal of Biosystems Engineering
• /
• 제29권4호
• /
• pp.329-334
• /
• 2004

This study was conducted to investigate the characteristics of transmittance spectrum of Korean red ginseng using VIS/NIR spectroscopy. The results of this study were as follows; Light intensity affected the characteristics of the spectrum. For over 40% light intensity, the first and second peaks appeared at 700nm and 1,100nm, respectively. For the 20% light intensity, the first and second peaks appeared at 800nm and 1,100nm, respectively. Thus, the typical color characteristics of halogen lamp were similar to each other if over 40% of maximum light intensity power, otherwise it was not. Transmittance spectrum showed different characteristics at different portions of red ginseng. Normal red ginseng showed strong intensity at the first peak around 700nmbecause of reddish internal tissue. However, an internal white core red ginseng showed weak peak-intensity due to whitish internal tissue. There was no significant difference in the second peak at 800nm for the different internal qualities. Third peak at 900nm showed somewhat difference by internal qualities but it was difficult to find significant trend. To separate the differences of the internal qualities, intensity differences between peaks were used. It was possible to classify normal red ginseng by the differences of "peak 1 -peak 2" and "peak 1 - peak 3". In addition, shift of the first and the third peaks in the spectrum could separate normal red ginseng from others.ginseng from others.

• 한국노년학
• /
• 제36권3호
• /
• pp.827-846
• /
• 2016

본 연구는 개인적 생애 과정의 다기화에 따른 연령분절적 사유의 한계와 임금피크제에 대한 경영효율성 중심의 계량화 된 성과평가의 문제의식에 기초한다. 임금피크제의 적용을 받고 있는 노동자의 경험을 통해 임금피크제가 노동시장의 진출입이 연령에 의해 제한되지 않고 다양한 연령대의 노동자간 상호작용이 활발한 조직차원의 연령통합에 미치는 영향을 밝히고자 했다. 본 연구는 연구 주제에 대해 심층적으로 이야기해줄 수 있는 연구참여자 사례들을 선정하여 연구하는 질적사례 연구방법을 사용하였다. 본 연구는 특정한 이슈를 중심으로 복합적 사례들(stake 1995)을 해석학적으로 분석하는 본질적 사례 접근을 사용하였다. 연구결과, 이슈를 중심으로 찾은 의미들은 크게 3개의 하위 범주; '중고령 근로자의 고용연장과 직책해제로 인한 젊은 근로자들의 불편한 시선', '젊은 세대와 중고령 세대가 공생하기 힘든 고용현황으로 인한 중고령 근로자의 동전의 앞뒷면과 같은 처지', '의사소통과 공감대형성으로 세대 간 갈등을 해소하며 서로의 이점과 상생점 찾기'로 집합되었고 '임금피크제 시행으로 인한 중고령 근로자들의 고용변화가 빚은 세대 간의 갈등 은 서로의 의사소통과 공감노력을 통해 조직이 연령통합사회로 향하게 함.'라는 상위주제가 도출되었다.

• 대한통합의학회지
• /
• 제7권2호
• /
• pp.85-93
• /
• 2019

Purpose : The purpose of this study was to investigate the effects of abdominal functional electrical stimulation on peak cough flow and forced vital capacity in patients with cervical spinal cord injury. Methods : The study examined 20 patients with cervical spinal cord injury. The subjects were randomly divided into two groups. All subjects performed conservative physical therapy for 30 minutes. The experimental group also underwent abdominal functional electrical stimulation for at least 20 minutes per day. Abdominal functional electrical stimulation was applied to the rectus abdominis muscle twice each day, three times a week, for four weeks. In all subjects, the peak cough flow was measured using a peak flow meter and forced vital capacity was assessed using a spirometer. Results : The experimental group showed a significant increase in peak cough flow and forced vital capacity in pre-post measurements (p<.05), while the control group showed a significant increase only in peak cough flow. Conclusion : These findings suggest that conservative physical therapy in combination with the abdominal functional electrical stimulation can improve peak cough flow and forced vital capacity in patients with cervical spinal cord injury.

• 한국가금학회지
• /
• 제48권4호
• /
• pp.319-325
• /
• 2021

In this study, we investigated the effects of feeding diets with different levels of energy and nutrient density on the egg quality of laying hens during the pre-peak and peak periods. A total of 192 (Hy-line brown) laying hens were used in a 15-week trial. The hens were randomly allotted to one of four treatments, each with four replicates (12 hens per replication). We assessed the effects of four level of dietary energy (2,710, 2,850, 2,870 and 2,890 kcal/kg) and three levels of nutrient density (Methionine + Cysteine: 0.56%, 0.85%, 0.80% and Crude Protein: 14.5%, 19%, 18%). Differences in the energy and nutrient density contents of diets showed no significant effect (P>0.05) on the average daily gain, average daily feed intake, feed conversion ratio, egg weight, or egg production of hens during the pre-peak and peak periods. However, hens subjected to 2,890 kcal/kg during the pre-peak period were found to lay eggs with significantly thicker shells, and yolk color was found to be significant enhanced in hens fed this diet during the pre-and peak periods. In contrast, we detected no significant effects of dietary energy or nutrient density on the Haugh unit or eggshell strength. In summary, increasing the energy level of diets from 2,710 to 2,890 kcal/kg was found to have positive effects on the shell thickness and yolk color of eggs produced by laying hens.

• Restorative Dentistry and Endodontics
• /
• 제46권4호
• /
• pp.51.1-51.13
• /
• 2021

Objectives: This study aimed to evaluate the effect of improper positioning single-peak and multi-peak lights on color change, microhardness of bottom and top, and surface topography of bulk fill and incremental composites after artificial aging for 1 year. Materials and Methods: Bulk fill and incremental composites were cured using multi-peak and single-peak light-emitting diode (LED) following 4 clinical conditions: (1) optimal condition (no angulation or tip displacement), (2) tip-displacement (2 mm), (3) slight tip angulation (α = 20°) and (4) moderate tip angulation (α = 35°). After 1-year of water aging, the specimens were analyzed for color changes (ΔE), Vickers hardness, surface topography (Ra, Rt, and Rv), and scanning electron microscopy. Results: For samples cured by single-peak LED, the improper positioning significantly increases the color change compared to the optimal position regardless of the type of composite (p < 0.001). For multi-peak LED, the type of resin composite and the curing condition displayed a significant effect on ΔE (p < 0.001). For both LEDs, the Vickers hardness and bottom/top ratio of Vickers hardness were affected by the type of composite and the curing condition (p < 0.01). Conclusions: The bulk fill composite presented greater resistance to wear, higher color stability, and better microhardness than the incremental composite when subjected to improper curing. The multi-peak LED improves curing under improper conditions compared to single-peak LED. Prevention of errors when curing composites requires the attention of all personnel involved in the patient's care once the clinical relevance of the appropriate polymerization reflects on reliable long-term outcomes.

• 한국광학회:학술대회논문집
• /
• 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
• /
• pp.26-28
• /
• 1990

Cw arc 램프로 펌핑하는 Alexandrite 레이저의 형광을 optical Spectrum Analyzer를 이용하여 측정하였다. Vibronic 천이에 해당하는 광대역 형광 스펙트럼이 관측되었고, arc 램프 입력에 따른 peak 형광의 세기 및 peak intensity 파장의 입력 power 의존성을 조사하였다. 형광의 세기는 입력 power에 따라 0.16 /kw의 비율로 증가하였고, peak intensity 파장은 입력 power가 5kw 까지는 5 nm/kw 비율로 장파장쪽으로 이동하였다.

• 전자공학회논문지B
• /
• 제28B권7호
• /
• pp.590-598
• /
• 1991

This paper represents a syntactic peak detection algorithm which detects peak in the ECG signal.

• Bulletin of the Korean Chemical Society
• /
• 제33권10호
• /
• pp.3391-3396
• /
• 2012

Two-dimensional infrared (2D-IR) spectroscopy can probe the fast structural evolution of molecules under thermal equilibrium. Vibrational frequency fluctuation caused by structural evolution produced the time-dependent line shape change in 2D-IR spectrum. A variety of methods has been used to connect the evolution of 2D-IR spectrum with Frequency-Frequency Correlation Function (FFCF), which connects the experimental observables to a molecular level description. Here, a new method to extract FFCF from 2D-IR spectra is described. The experimental observable is the time-dependent frequency shift of maximum peak position in the slice spectrum of 2D-IR, which is taken along the excitation frequency axis. The direct relation between the 2D-IR peak shift and FFCF is proved analytically. Observing the 2D-IR peak shift does not need the full 2D-IR spectrum which covers 0-1 and 1-2 bands. Thus data collection time to determine FFCF can be reduced significantly, which helps the detection of transient species.