• 원예과학기술지
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• 제30권3호
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• pp.236-242
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• 2012

We investigated the influences of night interruption (NI) and night temperature on flowering and flower coloration in Cymbidium. Cymbidium 'Red Fire' and 'Yokihi' were grown under a 9 hours photoperiod (control), a 9 hours photoperiod with NI at a low light intensity (LNI) of 3-7 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, or a 9 hours photoperiod with NI at a high light intensity (HNI) of 120 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for four hours (22:00-02:00 HR) for 16 weeks during the reproductive growth stage (Experiment 1). Thirty month-old Cymbidium 'Red Fire' plants with initiated flowering buds were placed in four different growth chamber with night temperature set points of 6, 9, 12, or $15^{\circ}C$ for 16 hours (18:00 to 09:00 HR) and a daytime temperature of $25^{\circ}C$ (Experiment 2). In Experiment 1, the numbers of visible buds and flowers increased, and time to flowering decreased in both the LNI and HNI treatments, as compared to the control in both cultivars. Red color in Cymbidium 'Red Fire' increased by both LNI and HNI, as evidenced by an increased $a^*$ in plants grown under these conditions, relative to those grown under the control condition. Number of days to visible buds at 9-$15^{\circ}C$ ranged from 31-34 days, as compared to 39 days at $6^{\circ}C$ in Experiment 2. Although as the temperature increased days to flowering decreased when the plant was grown at $15^{\circ}C$ as compared to 6, 9, or $12^{\circ}C$, the red color ($a^*$) also decreased. The number of flowers and percent flowering increased when the night temperature was maintained higher than $9^{\circ}C$. Therefore, NI treatment and maintaining the night temperature at approximately 9-$12^{\circ}C$ during the winter season after flower spike initiation in the reproductive developmental growth stage improve flower quality and controls flowering time.

• 원예과학기술지
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• 제32권6호
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• pp.753-761
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• 2014

Growth and flowering of Cymbidium 'Red Fire' and 'Yokihi' plants were examined in a greenhouse with cooling systems in summer, and with night interruption (NI) lighting in winter as a forcing culture system. The greenhouse was divided into two sections with separate cooling controls during the summer season. One section was cooled by a mist system (mist), while the other section was cooled by a shade screen (shade). During the winter, the greenhouse was redivided into three sections within each cooling system. Plants were grown with NI either at a low light intensity of $3-7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(LNI) or a high l ight intensity of $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(HNI) u sing h igh-pressure sodium l amps during the 22:00-02:00 HR. The control plants were grown under 9 h short-day condition. NI for 16 weeks and cooling for 9 weeks were employed twice during the 2 years of the experimental period. The air temperature was approximately $2^{\circ}C$ lower in the mist than in the shade and the relative humidity was 80 ${\pm}5%$ in the mist compared to $55{\pm}5%$ in the shade. The daily light integral in the mist section was 48% higher than in the shade section. The time from initial planting to flowering pseudobulb emergence decreased with both LNI and HNI for both cultivars, regardless of the cooling treatments. Under NI conditions, however, between 60% and 1 00% of plants of both cultivars flowered in the mist, whereas no or 20% of 'Red Fire' or 'Yokihi' plants, respectively, flowered in the shade treatment over 2 years. Plants grown under the mist had bigger pseudobulbs than those grown in the shade under both NI treatments. These results show that commercial use of NI in winter and a mist cooling system in summer would decrease crop production time to 2 years and increase profits in Cymbidium forcing culture.

• 한국수자원학회논문집
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• 제54권11호
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• pp.915-924
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• 2021

본 연구에서는 전라북도 무주군 산지 유역의 사방댐 4개소를 대상으로 용량초과확률을 산정하였으며, 이를 통해 국내 사방댐 설계의 적정성과 산불피해에 따른 안전성을 분석하였다. 용량초과확률을 산정하기 위한 신뢰성 모형을 구축하였고 토사유출량 산정에는 MSDPM을 사용하였다. 재현기간(10년, 50년, 100년, 200년)별 강우강도를 사용하여 사방댐의 용량초과확률을 산정하여 비교 분석하였다. 그 결과 무주군 삼가리 유역의 사방댐 1개소와 증산리 유역의 사방댐 1개소는 과대설계 되었다고 판단되며 각각 사방댐의 용량을 61%, 47% 축소해도 안전할 것으로 판단된다. 또한 산불피해면적에 대한 사방댐의 용량초과 확률을 산정해 비교분석 하였으며 연구대상 유역에서 산불로 인한 영향이 가장 큰 곳은 삼가리 유역의 사방댐인 것으로 확인되었다.

• 한국지반공학회논문집
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• 제26권10호
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• pp.27-38
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• 2010

산지가 약 83%의 면적을 차지하는 강원지역에서는 매년 하절기에 장마, 태풍, 집중호우에 기인한 산사태 및 토석류와 같은 사면재해로 인해 많은 피해가 발생하고 있다. 본 연구에서는 강원도 지역의 사면재해를 유발하는 강우의 특성 분석을 위해 사면재해자료, 강우자료, 산불발생자료를 수집하여 DATABASE를 구축하였다. 구축된 자료에 대한 분석결과, 사면재해는 강우가 거의 없는 시점에 발생하는 경우가 많았으며, 사변재해를 유발하는 강우는 재해발생일의 강우보다 선행강우가 더욱 중요한 역할을 하는 것으로 나타났다. 또한 산불발생지역에서는 산불미발생생지역에 비하여 더 작은 강우에서도 사면재해가 발생하고 있으며 특히 산불발생지역에서는 2년이하의 재현강우에서 재해 발생빈도가 가장 높은 것으로 나타났다.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.320-330
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• 2020

화재는 높은 비정형성으로 인해 딥러닝 모델을 이용한 영상인식 분야에서도 좋은 성능을 내기가 어려운 대상 중 하나이다. 특히 지하공동구 내 화재는 딥러닝 모델의 학습을 위한 화재 데이터 확보가 어렵고 열약한 영상 조건 및 화재로 오인할 수 있는 객체가 많아 화재 검출이 어렵고 성능이 낮다. 이러한 이유로 본 연구는 딥러닝 기반의 지하공동구 내 화재 탐지 모델을 제안하고, 제안된 모델의 성능을 평가하였다. 기존 합성곱 인공신경망에 GoogleNet의 Inception block과 ResNet의 skip connection을 조합하여 어두운 환경에서 발생되는 화재 탐지를 위한 모델 구조를 제안하였으며, 제안된 모델을 효과적으로 학습시키기 위한 방법도 함께 제시하였다. 제안된 방법의 효과를 평가하기 위해 학습 후 모델을 지하공동구 및 유사환경 조건의 화재 문제와 화재로 오인할 수 있는 객체를 포함한 이미지에 적용해 결과를 분석하였다. 또한 기존 딥러닝 기반 화재 탐지 모델의 정밀도, 검출률 지표와 비교함으로써 모델의 화재 탐지 성능을 정량적으로 평가하였다. 제안된 모델의 결과는 어두운 환경에서 발생되는 화재 문제에 대해 높은 정밀도와 검출률을 나타내었으며, 유사 화재 객체에 대해 낮은 오탐 및 미탐 성능을 가지고 있음을 보여주었다.

• The Korean Journal of Ecology
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• 제19권5호
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• pp.417-430
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• 1996

This study was conducted to investigate the developmental process of plant community during the secondary succession and the dynamics of soil properties in the burned and unburned areas of Mt. Ch’oly-san. Owing to the forest fire occurred on April, 1989, the red pine(Pinus densiflora) forest and its floor vegetation were burned down. The floristic composition of burned and unburned areas were composed of 53 and 49 species of vascular plants, respectively. The dominant species based on SDR4 of the burned sites were lespedeza cyrtobotrya (89.62), Miscanthus sinensis var. purpurascens (62.50), and Carex humilis (58.73), Quercus serrata (43.33). In contrast, Pinus densiflora (83.56), Lespedeza cyrtobotrya (55.57), Miscanthus sinensis var. purpurascens (51.88) and Carex humilis (50.41) were dominant in the unburned area. The biological spectra showed the $H-D_1-R_5-e$ type in both the burned and unburned areas. The indices of similarity ($CC_S$) between the two areas were 0.74. Degree of succession (DS) was 604 in the burned area and 802 in the unburned area. From these facts, it is assumed that the succession is rapidly progressing because of the recovery of vegetation. The species diversity ($\={H}$) and evenness index(C) in the burned and unburned areas were 0.15 and 0.18, respectively. Red pine tree did not resprout after scorch by the forest fire, but Lespedeza, Quercus, Rhododendron, Albizzia, and Zanthoxylum resprouted from the roots and trunks after the forest fire. It seems that these species are the fire-resistant species. Soil properties such as soil pH, content of organic matter, available phosphous, total nitrogen, tatal carbon, exchangeable potssium, sodium, calcium, and magnesium increased due to forest fire. These results suggest the intensity of forest fire in the study area was relatively weak. Monthly changes of soil properties were of little significance except for some cases.

• 한국화재소방학회논문지
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• 제29권5호
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• pp.29-33
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• 2015

본 연구에서는 노즐의 형상변화에 따라서 방사유량, 살수분포 그리고 액적크기를 측정하였다. 이를 위해서 중심부 직경이 6.0 mm이고 반지름 방향 방사각도가 $142^{\circ}$와 $148^{\circ}$인 이중 구조의 미세 물분무 노즐(LPN142, LPN148) 형상을 제작하여 UL2167 시험규격에 의해서 살수분포와 분사거리의 관계를 정량화하였다. Hellium-Neon 레이져에 의한 광학적 분석 방법을 적용하여 방사유량 변화에 따라서 웨버 수와 액적 크기 그리고 방사각도에 관한 경험식을 구하였으며, 전달 방정식의 주요인자인 소멸 항과 액적크기의 상관관계를 분석하였다. 그 결과 이중 구조의 미세 물분무 노즐은 최소허용 유량범위가 결정된 경우 작동압력, 분사거리, 액적 직경을 예측하여 화재특성을 분석함으로써 노즐 선정이 가능할 것으로 사료된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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• pp.3475-3489
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• 2014

Here we present a simple flame detection method for an infrared (IR) thermal camera based real-time fire surveillance digital signal processor (DSP) system. Infrared thermal cameras are especially advantageous for unattended fire surveillance. All-weather monitoring is possible, regardless of illumination and climate conditions, and the data quantity to be processed is one-third that of color videos. Conventional IR camera-based fire detection methods used mainly pixel-based temporal correlation functions. In the temporal correlation function-based methods, temporal changes in pixel intensity generated by the irregular motion and spreading of the flame pixels are measured using correlation functions. The correlation values of non-flame regions are uniform, but the flame regions have irregular temporal correlation values. To satisfy the requirement of early detection, all fire detection techniques should be practically applied within a very short period of time. The conventional pixel-based correlation function is computationally intensive. In this paper, we propose an IR camera-based simple flame detection algorithm optimized with a compact embedded DSP system to achieve early detection. To reduce the computational load, block-based calculations are used to select the candidate flame region and measure the temporal motion of flames. These functions are used together to obtain the early flame detection algorithm. The proposed simple algorithm was tested to verify the required function and performance in real-time using IR test videos and a real-time DSP system. The findings indicated that the system detected the flames within 5 to 20 seconds, and had a correct flame detection ratio of 100% with an acceptable false detection ratio in video sequence level.

• 한국화재소방학회논문지
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• 제11권1호
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• pp.21-35
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• 1997

The natural convection and combined heat transfer induced by fire in a rectangular enclosure is numerically studied. The model for this numerical analysis is partially opened right wall. The solution procedure includes the standard k-$\varepsilon$ model for turbulent flow and the discrete ordinates method (DOM) is used for the calculation of radiative heat transfer equation. In numerical study, SIMPLE algorithm is applied for fluid flow analysis, and the investigations of combustion gas induced by fire is performed by FAST model of HAZARD I program. In this study, numerical simulation on the combined naturnal convection and radiation is carried out in a partial enclosure filled with absorbed-emitted gray media, but is not considered scattering problem. The streamlines, isothermal lines, average radiation intensity and kinetic energy are compared the results of pure convection with those of the combined convection-radiation, the combined heat transfer. Comparing the results of pure convection with those of the combined convection-radiation, the combined heat transfer analysis shows the stronger circulation than those of the pure convection. Three different locations of heat source are considered to observe the effect of heat source location on the heat transfer phenomena. As the results, the circulation and the heat transfer in the left region from heating block are much more influenced than those in the right region. It is also founded that the radiation effect cannot be neglected in analyzing the building in fire. And as the results of combustion gas analysis from FAST model, it is found that O2 concentration is decreased according to time. While CO and CO2 concentration are rapidly increased in the beginning(about 100sec), but slowly decreased from that time on.

• 한국화재소방학회논문지
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• 제33권4호
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• pp.16-27
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• 2019

실리콘 화합물인 Sodium silicate, 3-aminopropyltrimethoxysilane 졸, 3-(2-aminoethylamino) propylmethyl-dimethoxysilane 졸, 3-(2-aminoethylamino) propyltrimethoxysilane 졸로 표면 처리한 편백목재 시편의 연기 및 연소가스 발생에 대한 시험을 하였다. 실리콘 화합물 졸로 각각 편백목재 시험편에 붓으로 3회 칠하였다. 콘칼로리미터(ISO 5660-1)를 사용하여 연기 및 연소가스를 분석하였고 연기는 새로운 연기위험성 평가 방법을 적용하여 평가하였다. 실리콘 화합물로 처리한 목재시험편의 연기성능지수(SPI)는 편백목재보다 1.66~8.42배 증가하였고, 연기성장지수(SGI)는 11.8~88.2% 감소하였다. 연기강도(SI)는 편백목재보다 1.0~50.5% 감소되었고, 연기 및 화재 위험성이 낮아짐을 예측할 수 있었다. 실리콘화합물로 처리한 시험편의 세 번째 최대일산화탄소(CO_peak)농도는 공시편보다 22.5~33.3% 감소되었다. 그러나 미국직업안전위생관리국(OSHA) 허용기준(PEL)인 50 ppm보다 1.48~1.72배 높은 치명적인 독성을 발생시키는 것으로 측정되었다. 편백목재 자체는 일산화탄소 생성 농도가 높았지만 실리콘 화합물은 일산화탄소를 감소시키는 역할을 하였다.