• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.2023-2027
• /
• 2008

교통과 산업의 발달로 농촌인구의 감소가 빠르게 진행되고, 도시로 유입된 인구의 거주 공간 확보를 위해 도시주변의 피복 변화가 빠르게 진행되고 있다. 도시 지표의 대부분이 아스팔트나 콘크리트 등으로 피복되어 있어 도심의 기온이 교외와 비교하여 높게 형성되는 도시열섬현상(urban heat island, UHI)이 두드러지고 있다. 따라서 도시열섬현상 해소 대책으로 다양한 방법들이 분야 별로 제안되고 있다. 본 연구에서는 청주시 소재(미호천과 무심천을 대상으로) 하천으로 부터 떨어진 거리에 따른 열환경에 대하여 토지 피복에 따른 공간적 특성 분석을 수행함으로서 하천이 도심지 열 환경에 미치는 영향에 대하여 조사하였다. 하천을 중심으로 $0{\sim}1000m$ 까지 200m 간격의 버퍼를 생성하고 Landsat 영상에 의한 NDVI와 온도분포도를 이용하여 청주시 하천의 근접성에 따른 NDVI 및 온도 분포 분석 결과, NDVI는 하천을 기준으로 거리가 멀어질수록 점차적으로 증가하는 경향을 보였고 온도는 감소하는 것으로 나타났다. 또한 Quick-bird 영상에 의한 토지피복도와 NDVI, 온도 데이터를 중첩분석한 결과 NDVI는 산림-경작지-초지-나지-시가지 및 건조지 순으로 나타났고 평균온도는 NDVI의 역순으로 나타났다. 특히, 시가지를 비롯하여 공업지, 상업지 등 건조지역과 나지는 평균 $24^{\circ}C$ 이상으로 인구밀집지역은 높은 온도분포를 나타내는 것을 알 수 있었다.

• Korean Journal of Plant Resources
• /
• v.33 no.5
• /
• pp.476-481
• /
• 2020

In this study, we report a unrecorded plant on the Korean peninsula, Potamogeton × anguillanus Koidz. from Yeondangcheon (stream) in Yeondang-ri, Nam-myeon, Yeongwol-gun, Gangwon-do province. Potamogeton × anguillanus is a natural hybrid between P. wrightii Morong. and P. perfoliatus L. It is distinguished by its characteristic that the petiole is shorter than P. wrightii and that the leaf blade is narrower and longer than P. perfoliatus also, it didn't fully wrap the stem. Considering that P. × anguillanus is a natural hybrid, the name is given to it as 'Eol-chi-gi-dae-ga-rae'. We provide descriptions of the morphological characteristics, photographs, and key to allied taxa in Korea of P. × anguillanus.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.05a
• /
• pp.141-144
• /
• 2008

Atomization characteristics and spatial distribution of the spray emanating from an injector of liquid-propellant thruster are investigated by using dual-mode phase Doppler anemometry (DPDA). Spray characteristic parameters such as the mean velocity, Sauter mean diameter (SMD), and velocity fluctuation are measured at various locations along the spray axis as well as on the radial direction. Those data are quantified in radial profile and also used to scrutinize the correlation between diameter and turbulence intensity of spray droplets. For the better visual grasp, dynamic behavior of spray droplets along the spray stream is presented through the velocity vectors projected on the plane of geometric axis of nozzle orifice and radial coordinate.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.49 no.12
• /
• pp.277-284
• /
• 2012

In this paper, we analyzed various noise in the video stream system that have largely influence on EMI noise. We presented the remedy for these various noises and then designed the wireless video streaming system for a vehicle. To minimize EMI noise, we derived the improvement of noise characteristic from impedance matching, new design of the inner layer of the PCB line design and new design of high-speed data Interfaces. As a result, the final system showed 40[dBuV/m] and 47[dBuV/m] dB in the each regulation band.

• Journal of the Korean Society of Costume
• /
• v.50 no.6
• /
• pp.89-107
• /
• 2000

Underwear has undertaken the auxiliary role of outwear also. Thus, as outwear has changed forming the characteristic mode in every period, underwear has changed endlessly, so that it may match the form and function of outwear, in accordance with the stream of period. In this study, this researcher examined hoop and petticoat which were used for widening the skirt which is female clothes with diverse names in every period. under one name which is farthingale, centering around the West and korea, from 16th century to 20th century(the first term). In addition, it examined by comparison the relevancy between to the history and change factor of underwear which was used for swelling the skirt in Korean clothes. The result to have studied on the history and change factor about the farthingale of West and Korea is as follows: This study found that the silhouette of women's clothing has a strong relationship with underwear. Also The result to compare the underskirt of the West with that of Korea is as follows : They has other character, but in 18th century, being compared the underskirt of the West with that of Korea, for the swelling of skirt, this study found that they had something in common with the underskirt of the West and Korea.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.10 no.1
• /
• pp.96-101
• /
• 1986

The average heat transfer coefficient of 2-D impinging jet has been augmented as much as 60% on the wall with large-scale wavy roughness. The mechanism of this heat transfer augmentation is studied with emphasis on two primary flow structures in the impinging flow region by using either the surface floating method or the smoke-wire technique. They are the stream-wise vortex-like structure, which is characteristic to the impining jet, and the spanwise vortiecs associated with the flow separation around the roughness. The combined effect of these structures can effectively augment the heat transfer particularly in the downstream region where the teat transfer usually deteriorates consicerably.

• Asia pacific journal of information systems
• /
• v.25 no.2
• /
• pp.265-288
• /
• 2015

IT convergence services, as the main stream of the digital age, are currently on their way to include the concept of Software as a Service (SaaS), where IT products and services are integrated as one. In particular, the recently introduced web-service-based SaaS is expected to be a more developed SaaS model. This new model provides greater influence on clients' job performances than its previous models, such as application service providers and the web-native phase. However, the effects of technology maturity on task performance have been overlooked in adoption and performance studies. Accordingly, this study introduces SaaS technology maturity as the exogenous technological characteristic influencing job performance. This study also examines the relationships among various SaaS-related performances according to the different levels of SaaS maturity. Results suggest that applying innovative technologies (such as SaaS), particularly when the technology reaches a certain level of maturity, is more helpful for managers in improving task-technology fit and job performance. This study makes an academic contribution by establishing and validating a performance model empirically with SaaS technology maturity perspectives.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.12 no.5
• /
• pp.1-8
• /
• 2008

Dual-mode Phase Doppler Anemometry (DPDA) was used to scrutinize the spatial distribution characteristics of spray emanating from a small Liquid-Rocket Engine (LRE) injector. Droplet size and velocity were measured according to the variation of injection pressure along the plane normal to the spray stream and then the spray characteristic parameters such as Arithmetic Mean Diameter (AMD), Sauter Mean Diameter (SMD), number density, span of drop size distribution, and volume flux were deduced for an investigation of spray breakup characteristics. As the injection pressure increases, the number density, span, and volume flux of spray droplets become higher, whereas the AMD gets smaller.

• Journal of the Korean Society of Visualization
• /
• v.8 no.4
• /
• pp.60-65
• /
• 2010

A focus is given to the breakup behavior of spray droplets issuing from a nonimpinging-type injector. The analysis has been carried out experimentally by means of the dual-mode phase Doppler anemometry (DPDA). Spray characteristic parameters in terms of axial velocity, mean diameter, velocity fluctuation, and span (width of the size distribution) of droplets are measured down the geometric axis of a nozzle orifice and on the plane normal to the spray stream with the injection pressure variations. As the injection pressure increases, the velocity and its fluctuation become higher, whereas the droplet sizes get smaller. It is also shown that the magnitudes of those parameters are smoothed out by dispersion when the droplets move downstream as well as outwardly. The atomization process is significantly influenced by the injection pressure rather than the traveling distance in the experimental condition presented.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.50 no.6
• /
• pp.3-12
• /
• 2008

It is important to estimate accurate effective rainfall to analyse flood flow and long-term runoff for the rational planning, design, and management of water resource. The initial abstraction is also important to estimate effective rainfall. The Soil Conservation Service (SCS) has developed a procedure and it has been most commonly applied to estimate effective rainfall. But the SCS method still has weak points, because of unnatural assumptions such as antecedent moisture conditions and initial abstraction. The coefficient of initial abstraction(K) is depending on the soil moisture condition and antecedent rainfall. The maximum storage capacity of Umax which is calibrated by stream flow data in the proposed watershed was derived from the DAWAST(DAily WAtershed STreamflow) model. The values of K obtained from 69 storm events at the five watersheds are ranging from 0.133 to 0.365 and its mean value is 0.207. Effective rainfall could be estimated more reasonably by introducing new concept of initial abstraction. The equation of $K=0.076Sa^{0.255}$ was recommended instead of 0.2 and it could be applicable to the small-medium rural watersheds.