• 한국농촌생활과학회지
• /
• 제8권2호
• /
• pp.119-124
• /
• 1997

In this study we tried to give a decision on propriety of working conditions, to present ideas on reducing work loads, and to grope for efficiency of agricultural works. For this we examined the actual working conditions of cultivating welsh onion in the summer ground. And we improved harmful factors that affect farmer's health by considering results of previous study and farmer's subjective sensation. And we measured. compared, and analyzed the farmer's work loads before and after improvement. The results of this study are as follows ; 1. According to examine the actual working conditions of cultivating welsh onion in the summer ground, farmers have experienced physical and mental chronic fatigue on the basis of farmer's appel to eye - fatigue and sun - burned skin on hot working environment including excessive ultraviolet rays, the rough ground condition, inconsistent arrangement of working stand and sorter, heavy - weared habits, and unsuitable working posture. 2. When we improved harmful factors that affect farmer's health, conformed the effects on important work efficiency index such as heart rate, electromyovolume, body temperature, and microclimate inside clothing and work loads were decreased by eliminating the hillock and obstacles of ground, decreasing the clothing weight, using proper clothing appliances such as hat and sunglasses, controlling height of working stand and sorter suitably, improving the working postures and methods as using assistant appliances, alloting the working time and sequence effectively and presenting the light gymnastic exercises and rest for fatigue restoration.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
• /
• pp.533-536
• /
• 2007

The LiDAR data structure has the potential for modeling in three dimensions because the LiDAR data can represent voxels with z value under certain defined conditions. Therefore, it is possible to classify the physical damaged degree of vegetation by forest fire as using the LiDAR data because the physical loss of canopy height and width by forest fire can be relative to an amount of points reached to the ground through the canopy of damaged forest. On the other hand, biological damage of vegetation by forest fire can be explained using the NDVI (Normalized Difference Vegetation Index) which show vegetation vitality. In this study, we graded the damaged degree of vegetation by forest fire in Yangyang-Gun of South Korea using the LiDAR data for physical grading and digital aerial photograph including Red, Green, Blue and Near Infra-Red bands for biological grading. The LiDAR data was classified into 2 classes, of which one was Serious Physical Damaged (SPD) and the other was Light Physical Damaged (LPD) area. The NDVI was also classified into 2 classes which are Serious Biological Damaged (SBD) and Light Biological Damaged (LBD) area respectively. With each 2 classes ofthe LiDAR data and NDVI, the damaged area by forest fire was graded into 4 degrees like damaged class 1,2,3 and 4 grade. As a result of this study, 1 graded area was the broadest and next was the 3 grade. With this result, we could know that the burned area by forest fire in Yangyang-Gun was damaged rather biologically because the NDVI in 1 and 3 grade appeared low value whereas the LiDAR data in 1 and 3 grade included light physical damage like the LPD.

• 한국화재소방학회논문지
• /
• 제33권5호
• /
• pp.55-60
• /
• 2019

랙크식 창고에서 화재가 발생되는 경우 건물이 전소되거나 붕괴되는 상태까지 발생된다. 이러한 현상이 발생되는 이유는 랙크식 창고가 층고가 높고, 물품을 수직으로 적재하고 있어 화재 시 천장에 설치되어 있는 감지기에 의한 조기감지가 어렵고, 그로 인하여 초기에 소화하지 못하기 때문이다. 본 연구에서는 수치해석 프로그램인 Fire dynamic simulator (FDS)를 이용하여 랙크식 창고 내에서 화재 시 발생되는 열과 연기의 유동을 분석하였다. 이러한 분석을 통하여 랙크식 창고 내에서 조기 화재감지를 위한 화재감지기의 최적 설치조건을 확인하였다. 그 결과 랙크식 창고에서 조기 화재감지를 위하여 열과 연기의 복합적인 감지가 필요하며, 복합형 감지기를 랙크의 3 level 마다 설치해야 하며, 정온식 감지기는 랙크식 창고에 적합하지 않은 것을 알 수 있었다.

• Journal of Acupuncture Research
• /
• 제21권3호
• /
• pp.193-214
• /
• 2004

Objective : The purpose of this study is to investigate the mechanism and effect of moxibustion with ginger objectively, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxibustion with ginger. Methods : We have selected the indirect moxibustion with ginger among many indirect moxibustions. We produced a slice of ginger to a thickness of 3, 4, 5mm and the moxa cone having a diameter of 8mm, a height of 10mm for making a comparative study of characteristics of moxa cone according to change the density. We have made a comparative study of the thermodynamic characteristics of moxibustion with ginger with or without holes. We measured combustion times and calculated temperatures, temperature gradients in each period during a combustion of moxa. Results : 1. We found out it was not significantly influenced by the existence of the punched holes in a slice of ginger because the punched holes grow smaller immediately. 2. The duration of the preheating period became longer according to thickness of a slice of ginger and was not directly proportional to the density of moxa cone. The duration of the preheating period was extremely short when it burned a 100mg moxa cone. That was influenced by the density of moxa cone. 3. The duration of the heating period became longer according to thickness of a slice of ginger likewise the preheating period bacause the density of moxa cone had effected on the combustion characteristics. The duration of the heating period was extremely long when it burned a 100mg moxa cone. On the other hand the maximum temperature in the heating period was appeared that the combustion with a thin slice of ginger was highest and measured that the large density of moxa cone was higher. But the maximum temperature in the heating period was about $37.8^{\circ}C{\sim}44.2^{\circ}C$respectively lower in others. 4. The duration of the retaining period was some doubling shorter than that of the heating period that is concerned the shape of moxa cone. The temperature measured the close of a retaining period was $36.6^{\circ}C{\sim}41.8^{\circ}C$, that was considerably lower temperature. 5. The mean ascending temperature velocity and the mean descending temperature velocity were $0.042{\sim}0.073^{\circ}C/sec$, $-0.027{\sim}-0.064^{\circ}C/sec$ respectively. Then, the ascending temperature velocity was some faster than the ascending temperature velocity. Conclusions : The quantitative standard for obtaining the effective heating stimulation is that if the slice of ginger made a hole in it, we had to use the needle above 1.5mm diameter. The recommended size of a slice ginger is the 14mm diameter and the 2~3mm thickness. The moxa cone is formed the conical shape that the base diameter was 8mm, the height was 10mm, the density was $600mg/cm^2$.

• 한국농림기상학회지
• /
• 제17권3호
• /
• pp.207-216
• /
• 2015

본 연구는 산불 피해지에서 복원 방법 및 수종의 구성에 따라 미세 기후가 어떻게 변하는지에 관한 연구는 거의 이루어진 바 없어 산불 피해지에서 복원 방법 및 임분의 구성에 따라 임분 내 기상 패턴이 어떻게 변화하는지에 대해 구명하고자 수행되었다. 본 연구에서 사용된 독립 변수로 임분을 구성하는 수종의 종류와 생장, 임분 밀도, 그리고 피복율이며, 이에 따른 종속 변수로는 임분 내 광량, 기온, 습도, 토양 온도, 그리고 토양 수분 함량이었다. 기상 조건은 대부분 광 조건에 영향을 받는 종속 변수이나, 임분을 구성하는 수목의 생장과 피복률에도 변화하는 것으로 나타났다. 임분 내 습도는 임분 밀도와, 임분 내 기온과 수목의 수고와 음(-)의 상관 관계에 있는 것으로 나타나 임분 밀도와 수목의 생장이 증가할수록 임분 내부의 기온과 습도는 상대적으로 감소하는 경향을 보였다. 그러나 임분의 발달은 대부분 미세 기후의 전체 평균보다는 변동계수와 같은 편차를 줄이는 형태로 더 큰 영향을 주었으며, 수관 층의 수고와 임분 내 광량과 직접적인 관계에 있는 것을 감안하면($R^2$=0.87), 임분의 구조는 광량에는 직접적인 영향을, 다른 미세 기후에는 간접적인 영향을 준 것으로 사료된다. 한편 변동계수의 경우 삼척 지역이 고성 지역보다 상대적으로 높은 값을 보였으며, 수목의 생장에 따라 감소하는 경향을 보였다. 따라서 산불 발생 이후 시간 경과에 따라 상대적으로 안정된 상태를 지니는 것으로 해석되었다. 그러나, 현재 단계에서는 산불 피해 이후 숲의 발달에 따른 임분 내부의 기상 조건의 변화상을 뚜렷하게 확인하고 일반화하기에는 많은 어려움이 있어 이를 위해서는 보다 긴 시간에 걸쳐 많은 지점에서의 기상 조건과 임분 현황을 지속적으로 조사되어야 할 것이다. 이후 일반화된 자료를 활용한다면, 임분 구조와의 관계 해석은 물론, 하층 식생 출현 등에 대한 해석에 도움이 될 것으로 기대된다.

• Journal of Plant Biology
• /
• 제2권2호
• /
• pp.1-21
• /
• 1959

1. The plant communities on Mt. Sulak, a typical alpine mountain in central Korea was researched from the standpoint of ecological survey. 2. The plant on this mountain can largely be classified into 2 categories, the warm zone (below 1100m) and the frigid zone. The former is again classified into a broad-leaved tree formation and a needle-leved tree formation, and the latter is calssified into a broad-leaved tree formation and needle-leaved tree formation, and shrub formation. 3. The broad-leaved tree formation in the warm zone can largely be classified into a Carpinus laxiflora-syringa Palibiniana var. kanibayashi association(1), a Carpinus erosa-Acer Pseudo-sieboldianun association(2), and a Quercus mongolica- Tripterygium Regelii association(3). 4. The needle-leaved tree formation in the warm zone can also largely ben classified into a Pinus densiflora- Miscanthus sinensis association(4), Abies holophylla- Tripterygium regelii association(5), Pinus kordiensis- Rhododendron schlippenbachii association(6) In the association(4), the canopy of the Pinus densiflora is gradually being occupied by the Quercus mongolica which is one kind of broad-leaved trees. 5. We can fully see a DryoPteris type of the flour layer plant type in the association (3) and also see a Sasamorpha type in the association (5). 6. The broad-leaved tree formation in the frigid zone can largely be classified into Quercus mongolica- Rhododendron schlippenbachii association (8). The constituents of tree and subtree layers in (7) and (8) associations are similar to those association (3), but the constituents of the shrub layer are different from those of associtation (3) due to the difference in height. 7. The needle-leaved formation in the frigid zone can largely be classified into Thuja koraiensisRodgersia podophylla var. viritis association (9) and Abies nephrolepis-Acer tschonoskii var. rubripes asscciation (10). The species of alpine plants or subalpine plants are gradually increased in this formation. 8. The shrub formation can also largely be classified into a Rhododendron mucronulatum- Patrinia saniculaefolia association (11) and Pinus pumila associatio (12). Association (12) has largely developed on the windy place. Association (12) was burned due to the bombing during the Korean war, but now we recoginized there occurred an invasion of Tripterygium Regelii in such a place. 9. The herb layer species which constitute the shrub formation are mostly alpine or subalpine plants of small size, and their kinds are also very few. 10. The growth of the Moss layer is especially good because of the varied conditions of the habitat. The kinds which can easily be seen are the genus of Thunidium, Haplocladium, Brachythecium, Macromitrium, Holonitrium, Atrichum, Schwstchkeopsis, Grimmia, Hedwigia, Rhynchostegium and Mnium. 11. The genus of the Sphagnum densly grows like a mat at the acid and moisturous place above 1100m. The authors should express their thanks to father. Yang Kisup, Dean of Catholic Medical College, Prof. Yoon Doksuen, from their valuable advice. Thanks arealso due to Prof. Numata, Chiba University, Prof. Takagi, Nagoya University and Prof. Ando, Hiroshima University in Japan for his kind help and identification of Bryophytes.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2003년도 제20회 춘계학술대회 논문집
• /
• pp.91-93
• /
• 2003

A comprehensive numerical study is carried out to investigate for the understanding of the flow evolution and flame development in a supersonic combustor with normal injection of ncumally injecting hydrogen in airsupersonic flows. The formulation treats the complete conservation equations of mass, momentum, energy, and species concentration for a multi-component chemically reacting system. For the numerical simulation of supersonic combustion, multi-species Navier-Stokes equations and detailed chemistry of H2-Air is considered. It also accommodates a finite-rate chemical kinetics mechanism of hydrogen-air combustion GRI-Mech. 2.11[1], which consists of nine species and twenty-five reaction steps. Turbulence closure is achieved by means of a k-two-equation model (2). The governing equations are spatially discretized using a finite-volume approach, and temporally integrated by means of a second-order accurate implicit scheme (3-5).The supersonic combustor consists of a flat channel of 10 cm height and a fuel-injection slit of 0.1 cm width located at 10 cm downstream of the inlet. A cavity of 5 cm height and 20 cm width is installed at 15 cm downstream of the injection slit. A total of 936160 grids are used for the main-combustor flow passage, and 159161 grids for the cavity. The grids are clustered in the flow direction near the fuel injector and cavity, as well as in the vertical direction near the bottom wall. The no-slip and adiabatic conditions are assumed throughout the entire wall boundary. As a specific example, the inflow Mach number is assumed to be 3, and the temperature and pressure are 600 K and 0.1 MPa, respectively. Gaseous hydrogen at a temperature of 151.5 K is injected normal to the wall from a choked injector.A series of calculations were carried out by varying the fuel injection pressure from 0.5 to 1.5MPa. This amounts to changing the fuel mass flow rate or the overall equivalence ratio for different operating regimes. Figure 1 shows the instantaneous temperature fields in the supersonic combustor at four different conditions. The dark blue region represents the hot burned gases. At the fuel injection pressure of 0.5 MPa, the flame is stably anchored, but the flow field exhibits a high-amplitude oscillation. At the fuel injection pressure of 1.0 MPa, the Mach reflection occurs ahead of the injector. The interaction between the incoming air and the injection flow becomes much more complex, and the fuel/air mixing is strongly enhanced. The Mach reflection oscillates and results in a strong fluctuation in the combustor wall pressure. At the fuel injection pressure of 1.5MPa, the flow inside the combustor becomes nearly choked and the Mach reflection is displaced forward. The leading shock wave moves slowly toward the inlet, and eventually causes the combustor-upstart due to the thermal choking. The cavity appears to play a secondary role in driving the flow unsteadiness, in spite of its influence on the fuel/air mixing and flame evolution. Further investigation is necessary on this issue. The present study features detailed resolution of the flow and flame dynamics in the combustor, which was not typically available in most of the previous works. In particular, the oscillatory flow characteristics are captured at a scale sufficient to identify the underlying physical mechanisms. Much of the flow unsteadiness is not related to the cavity, but rather to the intrinsic unsteadiness in the flowfield, as also shown experimentally by Ben-Yakar et al. [6], The interactions between the unsteady flow and flame evolution may cause a large excursion of flow oscillation. The work appears to be the first of its kind in the numerical study of combustion oscillations in a supersonic combustor, although a similar phenomenon was previously reported experimentally. A more comprehensive discussion will be given in the final paper presented at the colloquium.

• 자원리싸이클링
• /
• 제31권6호
• /
• pp.44-51
• /
• 2022

현재 전기로(EAF) 제강 공정에서는 내화재 보호 및 탈황능 개선을 위해 MgO 함유 Flux인 경소돌로마이트를 사용하고 있으며, 탈산 효과와 동시에 Slag foaming을 통한 전력에너지를 저감시키기 위해 가탄제를 투입하고 있다. 본 연구에서는 상기 효과들을 경제적으로 달성하기 위해 폐 MgO-C계 내화재를 사용하고자 한다. 폐 MgO-C계 내화재는 현재 대부분 재활용되지 못하고 폐기되고 있는 실정이지만 다량의 MgO와 흑연 성분을 함유하고 있어 제강용 Flux로서의 효용가치가 입증되면 대량 재활용이 가능할 것으로 기대된다. 본 실험에서는 상용 EAF slag 조성을 토대로 Target 조성 범위를 설정하였다. Target EAF slag가 원만히 형성될 수 있도록 하기 위해 Flux와 함께 투입될 Pre-melt base slag를 제조하였다. Pre-melt base slag는 SiO₂, Al₂O₃, FeO를 혼합하여 알루미나 도가니에 장입 후 1450℃에서 1시간 이상 가열하여 제조하였다. 이후 제조된 Pre-melt base slag에 혼합 Flux #2(경소돌로마이트+폐 MgO-C계 내화재+석회석)을 가하여 용융반응 시험을 수행하고 그 결과를 기존 제강 Flux에 해당하는 혼합 Flux #1(경소돌로마이트+석회석) 경우와 비교 평가하여 그 대체 가능성을 평가하였다. 신뢰성있는 평가를 도출하기 위해 XRD, XRF 및 Slag foam height, Slag basicity, 철 회수 등의 평가를 종합하였다.

• 미술자료
• /
• 제104권
• /
• pp.10-39
• /
• 2023

충청남도 보령에 위치한 성주사(聖住寺)는 낭혜화상(朗慧和尙) 무염(無染, 800~888)이 창건한 사찰이다. 무염은 중국 유학을 마치고 귀국한 후 잠시 수도 경주에 머물다 김인문(金仁問, 629~694)의 후손들이 관리하던 사찰에 주석하였다. 이곳에서 무염은 불타고 남은 사찰을 중수하여, 847년에 선종사찰 성주사로 개창하였다. 이후 성주사는 사세가 번창하였고, 사역 내 여러 전각이 들어서며 대규모 가람의 모습을 갖추었다. 지역 내 성주사의 영향력은 「숭암산성주사사적(崇巖山聖住寺事蹟)」에서 살펴볼 수 있다. 「숭암산성주사사적」을 보면 성주사에 건립된 불전은 모두 73간으로 전한다. 이 중에서 주목되는 기록은 '전단림구간(栴檀林九間)'이다. 전단림구간은 '전단으로 지어진 건물이 9간' 혹은 '전단을 보관한 곳이 9간'이라는 의미가 될 수 있다. 해석의 차이는 있지만, 성주사에 전단이 많았음을 알 수 있다. 이 시기 전단은 유향목재(有香木材)로 동남아시아 자바나 수마트라에서 생산되었다. 장보고 사후, 서남해안일대를 장악한 군소 해상세력이 동남아시아 전단을 대량으로 입수하여 성주사에 시주한 것으로 보인다. 문성왕대 김양(金陽, 808~857)은 무열왕계인 자신의 입지를 강화하기 위해 지역 내 명망이 높았던 무염의 성주사를 후원하여 왕실과 성주산문을 잇는 가교 역할을 하였다. 원성왕계 왕실에서는 성주사를 지방 거점사찰로 삼아 반왕실적인 기운이 남아있는 지역에서 왕실의 권위를 회복하고자 하였다. 무염은 사찰을 수호하고, 민심을 교화하고, 나아가 지역의 안정을 도모하기 위해 철불을 조성한 것으로 추정된다. 성주사 문도가 2,000여 명에 달할 정도로 사세가 확장되었다는 점에서, 성주산문의 중심사찰인 성주사에 봉안된 철불은 지역의 민심을 결집하는 하나의 존상(尊像)으로 인식되었을 것이다. 성주사 철불은 모두 2구로 확인되며, 현재 전하는 철불편과 대좌의 크기로 볼 때 각각 금당과 삼천불전에 봉안된 것으로 보인다. 금당에 봉안된 철불1은 2m가 넘는 대형 철불이고, 삼천불전에 봉안된 철불2는 1m가 넘는 중형 철불로 판단된다. 「숭암산성주사사적」을 보면 '개창선법당오층중각(改創選法堂五層重閣)'이라는 기록이 전하는데, 이를 통해 성주사 개창시 철불1과 같은 대형 불상을 봉안하기 위해 중층식 금당이 건립되었음을 알 수 있다. 또한 철불1은 「성주사비(聖住寺碑)」와 손가락편의 모양을 통해 시무외여원인(施無畏與願印)을 결한 불상으로 추정된다. 성주산문은 동시기의 실상사(實相寺), 보림사(寶林寺), 삼화사(三和寺)와 같이 노사나불(盧舍那佛)을 주존불로 조성하였을 가능성이 높다. 무염이 초년에 화엄을 수학하였고 귀국 후 왕실의 후원을 받았다는 점에서, 신라하대 왕실을 중심으로 한 화엄종의 복고적인 경향이 선종사찰 성주사에도 반영된 것으로 생각된다.